Statistics Questions

To predict future enrollment in a school district fifty households within the district were sampled and asked to disclose the number of children under the age of five living in the household The results of the survey are presented in the table Complete parts a through c below a Construct a relative frequency distribution of the data Number of Relative Children under 5 Frequency 0 0 32 1 0 26 2 0 26 3 0 1 4 0 06 Type integers or decimals Do not round b What percentage of households has two children under the age of 5 Number of Children Number of under 5 0 1 2 3 4 Households 16 13 13 5 3

The following frequency histogram represents the IQ scores of a random sample of seventh grade students IQs are measured to the nearest whole number The frequency of each class is labeled above each rectangle Use the histogram to answers parts a through g B 60 70 C 150 159 D 60 69 f What percent of students had an IQ of at least 120 23 Type an integer or a decimal Do not round g Did any students have an IQ of 163 OA Yes because there is a bar in the 150 159 class OB Yes because there is a frequency of a score of 165 OC No because there is a bar in the 150 159 class Frequency 80 60 40 20 0 IQs of 7th Grade Students 13 40 54 43 32 9 3 2 13 60 70 80 90 100 110 120 130 140 150 160 IQ scores

represents scores of a random sample of seventh grade students IQs are measured to the nearest whole number The frequency of each class is labeled above each rectangle Use the histogram to answers parts a through g B TUU 109 c 100 110 OD 90 99 e Which class has the lowest frequency A 65 OB 60 70 O C 150 159 D 60 69 f What percent of students had an IQ of at least 120 Frequency 80 60 40 20 0 13 40 54 43 32 9 3 2 13 60 70 80 90 100 110 120 130 140 150 160 IQ scores

The following data represent the ages of award winners for best actor and best actress in a leading role for the 20 years from 1985 to 2004 Answer parts a b below Full data set 30 40 52 51 33 45 Best Actor Ages 36 51 47 52 26 36 36 62 30 43 63 36 48 44 a Construct an ordered back to back stem and leaf display Best Actor Age 2 3 4 5 6 27 63 30 Best Actress Ages 29 25 39 31 43 47 41 20 34 52 38 26 71 Best Actress Age 30 37 34 24

The accompanying data represent the percentage of recent high school graduates graduated within 12 months before the given year end who enrolled in college in the fall Construct a time series plot and comment on any trends Click the icon to view the data table Choose the correct time series plot below OA Percent Enrolled College Enrollment 70 64 58 1989 M 1997 2005 Year Q OB Percent Enrolled College Enrollment 70 64 584 www 1997 Year 1989 2005 2 O C Percent Enrolled College Enrollment 70 64 584 1989 1997 Year 2005

The data in the table represent the tuition for all 2 year community colleges in a region in 2014 2015 a Construct a cumulative frequency distribution b Construct a cumulative relative frequency distribution c Draw a frequency polygon d Draw a relative frequency ogive Tuition Number of dollars Community Colleges 775 799 800 824 825 849 850 874 875 899 900 924 925 949 950 974 20 68 14 5 0 0 0 1 H a Complete the cumulative frequency distributi Tuition dollars 775 799 800 824 825 849 850 874 875 899 900 924 925 949 950 974 Cumulative Frequency

The following data represent the number of grams of fat in breakfast meals offered at a local fast food restaurant a Construct an ordered stem and leaf plot and b describe the shape of the distribution 15 24 17 25 2 3 4 31 31 43 2 13 12 13 12 30 21 5 8 28 2 10 18 D 3 24 a Construct the ordered stem and leaf plot below Legend 5 1 represents 51 grams of fat

Is the following statement true or false When plotting an ogive the plotted points have x coordinates that are equal to the upper limits of each class The statement is

vny houldn t classes overlap when summarizing continuous data in a frequency or relative frequency distribution Choose the correct answer below OA Classes shouldn t overlap so that the distribution is not skewed in one direction OB Classes shouldn t overlap so that the class width is as small as possible OC Classes shouldn t overlap so that they are open ended D Classes shouldn t overlap so there is no confusion as to which class an observation belongs

What is an ogive Choose the correct answer below OA A graph that represents the cumulative frequency or cumulative relative frequency for the class OB A circle divided into sectors each sector representing a category of data OC A graph that uses points connected by line segments to represent the frequency or relative frequency for class OD A bar graph whose bars are drawn in decreasing order of frequency or relative frequency

The claim is that weights grams of quarters made after 1964 have a mean equal to 5 670 g as required by mint specifications The sample size is n 32 and the test statistic is t 2 339 Use technology to find the P value Based on the result what is the final conclusion Use a significance level of 0 05 State the null and alternative hypotheses Hou H Type integers or decimals Do not round The test statistic is Round to two decimal places as needed The P value is Round to three decimal places as needed Based on the P value there sufficient evidence at a significance level of 0 05 to that weights of quarters made after 1964 have a mean equal to 5 670 g as required by mint specifications the claim

The piston diameter of a certain hand pump is 0 6 inch The manager determines that the diameters are normally distributed with a mean of 0 6 inch and a standard deviation of 0 005 inch After recalibrating the production machine the manager randomly selects 23 pistons and determines that the standard deviation is 0 0043 inch Is there significant evidence for the manager to conclude that the standard deviation has decreased at the a 0 05 level of significance What are the correct hypotheses for this test The null hypothesis is Ho The alternative hypothesis is H Calculate the value of the test statistic x Round to three decimal places as needed Use technology to determine the P value for the test statistic The P value is Round to three decimal places as needed What is the correct conclusion at the a 0 05 level of significance Since the P value is than the level of significance the null hypothesis There evidence to conclude that the standard deviation has decreased at the 0 05 level of significance sufficient

The data given to the right includes data from 40 candies and 10 of them are red The company that makes the candy claims that 30 of its candies are red Use the sample data to construct a 95 confidence interval estimate of the percentage of red candies What do you conclude about the claim of 30 Construct a 95 confidence interval estimate of the population percentage of candies that are red p Type an integer or decimal rounded to one decimal place as needed Is the result consistent with the 30 rate that is reported by the candy maker O No because the confidence interval does not include 30 O Yes because the confidence interval includes 30 Weights g of a Sample Bag of Candy Yellow 0 934 0 739 0 915 0 985 0 735 0 743 0 887 Red Blue Brown Green 0 912 0 819 0 773 0 737 0 744 0 734 0 814 0 942 0 858 0 836 0 985 0 815 0 973 0 859 0 959 0 816 0 893 0 998 0 806 0 767 0 835 0 808 0 767 0 838 0 938 0 985 0 903 0 906 0 912 0 754 0 869 0 813 0 893

If A is any event then the event that isn t A is ca A

Review the information and layout of the four part hazmat diamonds You will have an opportunity to demonstrate your knowledge of how information is communicated through the diagrams Below are two hazmat diamonds for two different mystery substances 04 2141 W Hazmat Diamond for Unknown Substance 1 74 4 0 00 0 17 You can earn a maximum of 20 points for this assignment Part One For each substance COR Hazmat Diamond for Unknown Substance 2 Click here for an audio description of the image Directions Review the hazmat diamond for each of two unknown mystery substances Using complete sentences thoroughly describe both mystery substances in terms of flammability reactivity health and special information Be sure to correctly refer to either the color blue red yellow white or the location left top right bottom diamonds to explain what the number means relative hazard as well as any special notes or information Accurate description and explanation of left blue top red and right yellow using proper terminology 3 points for each substance Accurate description and explanation of the bottom white diamond using proper terminology 2 points for each substance Part Two Which substance do you think is most dangerous and why Support your statement 5 points

5 3 8 2 5 1 3 Total GB LAST MONTH S DATA 151 63 Overall Daily

The average amount of money spent for lunch per person in the college cafeteria is 7 06 and the standard deviation is 2 49 Suppose that 9 randomly selected lunch patrons are observed Assume the distribution of money spent is normal and round all answers to 4 decimal places where possible a What is the distribution of X X N b What is the distribution of a N c For a single randomly selected lunch patron find the probability that this patron s lunch cost is between 5 94 and 6 98 d For the group of 9 patrons find the probability that the average lunch cost is between 5 94 and 6 98 e For part d is the assumption that the distribution is normal necessary Yes No

5 According to a recent survey the probability that the driver in a fatal vehicle accident is female event F is 0 2105 The probability that the driver is 24 years old or less event A is 0 1818 The probability that the driver is female and is 24 years old or less is 0 0418 Answer parts a through d below a Find the probability of FUA P FUA b Find the probability of F UA P F UA c Find the probability of FNA Round to four decimal places as needed Round to four decimal places as needed P FNA d Find the probability of F UA P F UA Round to four decimal places as needed Round to four decimal places as needed

national survey asked people How often do you eat out dinner instead of at home The frequencies were as lows Complete parts a through g Response Never Rarely Sometimes Most of the time Always Frequency 239 457 942 325 61 I 3 Round to one decimal place as needed c What percentage of respondents answered Never or Rarely 34 4 Round to one decimal place as needed d Construct a frequency bar graph Choose the correct answer below O A B O C Frequency Frequency quency 1000 750 500 250 1000 750 500 250 1000 750 500 L NRSMA NRSMA

The following data set provides information of the 20 largest cities by population to compare 2000 to 2010 Rank 1 2 3 4 5 6 7 8 9 10 City New York NY Los Angeles CA Chicago IL Houston TX 17 18 19 20 Philadelphia PA Phoenix AZ San Antonio TX San Diego CA Dallas TX San Jose CA 11 Louisville KY 12 Jacksonville FL 13 Indianapolis IN 14 San Francisco CA 15 16 Austin TX Columbus OH Fort Worth TX Charlotte NC Detroit MI El Paso TX 2000 Population 2010 Population 8 008 278 8 175 133 3 694 820 3 792 621 2 896 016 2 695 598 1 953 631 2 099 451 1 517 550 1 526 006 1 321 045 1 445 632 1 144 646 1 327 407 1 223 400 1 307 402 1 188 580 1 197 816 894 943 945 942 741 096 821 784 820 445 805 235 790 390 787 033 741 206 731 424 713 777 649 121 735 617 781 870 776 733 656 562 711 470 534 694 540 828 951 270 563 662 Duane is interested in investing in real estate in a major city It is important for him to know about the growth of the population so he does not invest in a stagnant area He is looking at assumed normally distributed growth since 2000 within the 20 largest cities This data set has a population standard deviation of 18 603 what is the minimum sample size to be 99 confident that the sample mean is within 100 of the true population mean Z0 10 20 05 Z0 025 2001 Zo 005 1 282 1 645 1 960 2 326 2 576 Use the table above for the z score Round only at the final step and remember to round up to the closest integer Provide your answer below Comments Achieved population peak in 2010 Achieved population peak in 2010 Achieved population peak in 2010 Achieved population peak in 2010 Achieved population peak in 2010 Achieved population peak in 2010 Achieved population peak in 2010 Achieved population peak in 2010 Achieved population peak in 2010 Achieved population peak in 2010 Achieved population peak in 2010 Achieved population peak in 2010 Achieved population peak in 2010 Achieved population peak in 2010 Achieved population peak in 2010 Achieved population peak in 2010 Achieved population peak in 2010

Given the following table of scores calculate the indicated locator and percentile Do not round your results 680 18 36 49 9 11 14 15 20 25 29 30 37 39 42 47 a Calculate the locator for the 72th percentile L72 L72 52 5 b Determine the 72th percentile P72 P72 c Approximately what percent of the scores in a dataset are above the 72th percentile 47 4 Enter an integer or decimal number more 8 pts 1

Compute the least squares regression equation for the given data set Round the slope and y intercept to at least four decimal places y 1 1 6 3 Send data to Excel 5 6 2 5 Regression line equation y 3 4

Question A recent graduate moving to a new job collected a sample of the monthly rent in dollars and the size in square feet of 3 bedroom apartments in one area of a city Use Excel to find the best fit linear regression equation where size of the apartment is the explanatory variable Round the slope and intercept to two decimal places Help Size 961 924 920 902 893 888 886 876 Rent 909 1048 841 Provide your answer below 704 1131 867 2532 800 1030 Copy to Clipboard Open

A popular charity used 29 of its donations on expenses An organizer for a rival charity wanted to quickly provide a donor with evidence that the popular charity has expenses that are higher than other similar charities The organizer randomly selected 20 similar charities and examined their donations The charity conducts a one mean hypothesis at the 5 significance level to test whether the mean is less than 29 a Ho 29 Ha 29 which is a left tailed test b The percentages of the donations that those 20 charities spend on expenses are given below Use Excel to test whether the mean is less than 29 Identify the test statistic t rounding to two decimal places and p value rounding to three decimal places from the Excel output 9 24 14 25 2 3 2 3 2 2 3 31 23 37 19 25 31 Help Copy to Clipboard Download CSV

Question The following data set provides information on wholesale sales by establishments and by total sales Wholesale 1 Wholesale 2 Wholesale 3 Merchants 1 Merchants 2 Merchants 3 Mean Standard Deviation Number of Establishments Round 5378 4696 160 4856 4696 160 3324 3 2463 8 Product Total sales as sales in a of billions total sales 11 6 8 7 27 2 11 5 8 7 27 2 15 8 Provide your answer below 273 202 36 238 202 36 164 5 103 A cheese merchant looks again at the data set about total cheese sales in which the sample mean is 164 5 and the sample standard deviation is 103 Find the 95 confidence interval estimate your answer to ONE decimal place 8 9

In Hawail shark attacks are very rare Furthermore about 55 of all shark attacks are serious but not fatal You are scheduled to give a talk at a local scuba club in Honolulu and want to include a brief statistical profile regarding the most recent five shark attacks all of which were nonfatal Let r be the number of nonfatal attacks out of a random sample of five shark attacks a Make a histogram for the probability distribution of r 0 35 0 30 O 0 25 0 20 0 15 0 10 0 05 0 0 35 0 30 0 25 0 20 0 15 0 10 0 05 0 0 0 1 1 2 2 r r 3 3 4 4 5 5 P r 0 35 0 30 0 25 0 20 0 15 0 10 0 05 of the five 0 35 0 30 0 25 0 20 0 15 0 10 0 05 0 0 0 1 1 2 2 r 3 3 4 4 5 5 b What is the probability all five shark attacks are nonfatal Round your answer to three decimal places 0 050 c What is the probability that two or more of the five shark attacks are nonfatal Round your answer to three decimal places

A hypothesis test is performed at the 10 significance level to determine if the mean student loan debt in thousands of dollars of students at private universities and public universities are different The hypotheses were determined and data was collected in the table below for both samples Private Public Ho M M2 Ha M M2 0 1 O O What is the test statistic t value for this two mean hypothesis test Select the correct answer below O Sample Size Sample Mean Sample St Dev 5 2 2 0 t t 25 1 11 8 28 18 5 2 5 2 2 28 2 18 25 1 11 8 28 18 28 18 25 1 2 11 8 2 5 2 25 1 11 8 5 2 2 28 18 5 2 2 28 18 5 2 2 25 1 2 11 8 2 28 18 2 0 75 0 42 0 72 12 2 0 58 25 1 11 8 8 4

For the following data set x y Send data to Excel Part 1 of 2 8 4 Part 1 2 4 Part 2 of 2 3 6 31 12 36 The coefficient of determination is 0 513 9 0 a Use a TI 84 calculator to compute the coefficient of determination Round the answer to at least three decimal places 3 4 5 11 3 16 b How much of the variation in the outcome variable is explained by the least squares regression line Round the answer to at least one decimal place The percentage of the variation in the outcome variable is explained by the least squares regression line is

1 A random variable X that assumes the values X X X is called a discrete uniform random variable if its probability mass function is f x for all X X2 X and 0 otherwise Find the mean and variance of X UB K C k i 1 OD K X i 1 Determine the expression that represents the variance o Choose the correct answer below W OA 1 k OB x i 1 k OC K X H i 1

Banana Bay Banyan Tree 5 Beach Castle 6 Best Western 7 Cabana 10 Coconuts 17 Ramada 18 Sandpiper 11 Diplomat 12 Holiday Inn 19 Sea Castle 13 Lime Tree 20 Sea Club 14 Outrigger 21 Sea Grape or reference the resorts have been labelled with 2 digit numbers You need to USE THIS TABLE of random digits to select an SRS n 4 of these esorts for the campus newspaper to call 29077 95052 27102 14863 90908 56027 61683 73592 55892 24 Sunset Beach 25 Tradewinds 26 Tropical Breeze 27 Tropical Shores 28 Veranda umbers here 47052 75186 33063

Compute the least squares regression line for predicting y from x given the following summary statistics Round the slope and y intercept to at least four decimal places x 8 8 S 15 000 Sx 2 2 r 0 50 Send data to Excel y 100 Regression line equation y 3409 0909x 2990 5 2 0

The owners of a fast food franchise looking to reduce wait times for customers launched a prot could use a smartphone app to place orders The accompanying data set shows the mean wait times in seconds for in store and drive through customers at 30 restaurants participating in the pilot program and at 30 restaurants not participating in the program Assume that the population standard deviation of mean wait times is 30 seconds for both groups of restaurants and that the mean wait times are normally distributed for both groups of restaurants Let the mean wait times at the restaurants not in the program be the first sample and let the mean wait times at the stores in the program be the second sample At the 0 05 level of significance is there evidence that the smartphone app reduces wait times Perform the test using Excel Find the test statistic rounded to two decimal places and the p value rounded to thre decimal places Mean Wait Time Not In Program 265 282 269 274 309 277 304 324 291 Help Copy to Clipboard Mean Wait Time Program 264 210 234 244 227 212 182 295 225 Download CSV

1 POINT We are doing a two mean pooled test We have two samples with sizes n 23 and n 15 The population standard deviations are unknown but assumed to be equal so we find the sample standard deviations and use them to calculate a pooled standard deviation Sp What are the test statistic 1 and the degrees of freedom to perform this test Select the correct answer below O O O For sample 1 s 15 and x 45 For sample 2 S2 15 6 and 41 O O If sp 15 236 then 23 15 t 15 236 LII V 45 df 38 If sp 15 236 then 45 41 t 15 236 A V df 38 If sp 15 236 then Sp 45 41 t 15 236 df 36 If Sp 15 236 then 45 41 df 38 TTS If Sp 15 236 then 23 15 t 0 79 15 236 15 15 236 I df 36 15 236 If sp 15 236 then Sp 23 15 t df 36 VISI 2 43 I T 2315 1 22 0 79 2 43 1 58

The probability distribution of X the number of imperfections per 10 meters of a synthetic fabric in continuous rolls of uniform width is given by the accompa table Find the average number of imperfections per 10 meters of this fabric X f x 0 0 41 1 0 37 2 0 16 3 0 04 4 0 02 The average number of imperfections per 10 meters of this fabric is Type an integer or a decimal Round to two decimal places as needed

Researchers are conducting a pooled right talled two mean hypothesis test at a 1 significance level The two samples 10 The samples have standard deviations of s1 7 and 2 6 respectively have sizes 1 H 11 and 1 After finding the degrees of freedom the next step is to find the critical value s for the hypothesis test Determine the critical value s for this test P Select the correct answer below O 2 518 O 2 518 O 2 831 2 831 O 2 539 df to 10 to 05 to 025 to 01 19 20 21 22 1 328 1 729 2 093 2 539 Round your answer s to three decimal places 1 323 1 721 1 325 1 725 2 086 2 528 2 845 2 080 1 321 1 717 2 074 to 005 2 861 2 518 2 831 2 508 2 819

A baseball pitcher concerned about losing speed from his fastball undertook a new training regimen during the offseason His team s pitching coach measured the speed of 20 random fastballs in miles per hour thrown by the pitcher during spring training and compared it with a sample of 20 random fastballs thrown during the pitcher s last five starts in the previous season The results are shown in the following table Assume that the pitcher s fastball speeds had a standard deviation of 2 9 miles per hour both before and after the training regimen and that the speeds for both time periods are normally distributed Let the pitcher s fastball speeds in the previous season be the first sample and let the pitcher s fastball speeds in spring training be the second sample At the 0 05 level of significance is there evidence that the pitcher is throwing fastballs at higher speeds Find the test statistic rounded to two decimal places and the p value rounded to three decimal places Last Season s Fastball 92 91 96 94 92 94 92 95 This Season s Fastball 90 95 93 94 91 95 97 92

The chief financial officer is monitoring the raises for each department The hypothesis is based on the premise that the management department has higher raises Determine the critical value or values for a one mean 2 test at the 2 significance level if the hypothesis test is two tailed Ha o If there is only one critical value leave the second answer box blank Provide your answer below 20 10 1 282 20 05 1 645 20 025 20 01 1 960 2 326 70 005 2 576

Cost Cost Number 9 8 17 3 37 8 10 6 19 7 38 2 11 8 20 5 38 7 12 5 35 5 22 3 39 2 13 7 36 4 24 0 39 5 Source Agency for Healthcare Research and Quality Part 1 of 2 Send data to Excel Number 34 3 34 2 34 9 a Compute the coefficient of determination Round the answer to at least three decimal places Part 1 2 The coefficient of determination is 0 97337 Part 2 of 2 b How much of the variation in mean cost of hospital stay is explained by the least squares regression line answer to at least one decimal place

Proc A certain region is on average hit by 5 7 hurricanes a year Find the mean and variance of the random variable X representing the number of hurricanes per year to mit the region The mean is Type an integer or a decimal Do not round

QUESTION 1 2 POINTS Some researchers are doing a two mean pooled t test They have two samples with sizes n 17 and n2 21 The population standard deviations are unknown but assumed to be equal so the sample standard deviations are found and used to calculate a pooled standard deviation Sp For sample 1 s 9 8 and 30 For sample 2 2 10 5 and 27 What are the test statistic t and the degrees of freedom to perform this test Select the correct answer below If Sp 10 195 then 17 21 t 10 195 7 df 38 If Sp 10 195 then 30 27 t df 36 11 10 195 V 17 21 df 36 If Sp 10 195 then 17 21 t 10 195 7 If sp 10 195 then 30 27 t 1 48 10 195 0 9 11 V 30 27 1 48 1 11

075 Q50 Exam Scc 85 6 About 25 of the students scored 40 20 or more

Here is the start of a 100 chart Without extending the chart determine which numbers should go in the shaded boxes Complete parts a and b a 79 HE

D L C D g s 1 i 1 F a 1 D s s O d O C O b O a

Use the figures below to answer parts a through c a How many rectangles are there in each of these figures Note that rectangles may measure 1 by 1 1 by 2 1 by 3 and s 1 rectangle 3 rectangles a a a b b b C 3 P rectangles rectangles

The following data set provides information on wholesale sales by establishments and by total sales Number of Establishments Total sales in billions Product sales as a of total sales 5378 273 11 6 4696 202 8 7 160 36 27 2 4856 11 5 4696 8 7 160 3324 3 2463 8 Wholesale 1 Wholesale 2 Wholesale 3 Merchants 1 Merchants 2 Merchants 3 Mean Standard Deviation Provide your answer below 238 202 68 confidence interval estimate 36 164 5 103 A cheese merchant examines the data set about the product sales of cheese as a of total sales in which the sample mean is 15 8 and the sample standard deviation is 8 9 Find the 68 confidence interval Round your answer to ONE decimal place 27 2 15 8 8 9

Get an education A survey asked 32 145 people how much confidence they had in educational institutions The results were as follows Round your answers to four decimal places if necessary Part 0 3 Part 1 of 3 Response A great deal Some Hardly any Total Number 10 016 17 867 4262 32 145 Send data to Excel a What is the probability that a sampled person has either a great deal or hardly any confidence in educational institutions or hardly any confidence in ola

rectangle has an area of 84 cm Its length and width are whole num a What are the possibilities for the two numbers b Which possibility gives the smallest perimeter a In centimeters what are the possibilities for the two numbers OA OB O C OD 1 84 5 17 3 28 1 84 2 42 5 17 1 84 5 17 3 28 1 84 2 42 3 28 7 12 4 21 11 8 7 12 13 6 6 14 7 12 11 8 13 6 7 12 4 21 6 14

Twenty adult males between the ages of 30 and 40 participated in a study to evaluate the effect of a specific health regimen involving diet and exercise on the blood cholesterol Ten were randomly selected to be a control group and ten others were assigned to take part in the regimen as the treatment group for a period of 6 months The accompanying table shows the reduction in cholesterol experienced for the time period for the 20 subjects Compute the sample variance and sample standard deviation for both control and treatment groups FEClick the icon to view the data on reduction in cholesterol The variance for the control group is The variance for the treatment group is Round to four decimal places as needed The standard deviation for the control group is The standard deviation for the treatment group is Round to four decimal places as needed GECCOR Cholesterol Reduction Control group Treatment group 7 2 7 12 6 27 2 35 k TIN 9 15 5436 1236 X

For each give a rule that describes the pattern for changing one number into the one beside it I 11 III Original 4 6 13 14 New 8 12 26 28 Original 4 6 13 14 New 16 36 169 196 Choose the rule below that describes I OA Square the number on the left B Double the number on the left C Subtract 2 from the number on the left D Triple the number on the left then subtract 2 Original 14 13 6 4 New 12 11 4 2

Suppose the times of delivery from an area distributor are normally distributed If the population standard deviation is 2 hours what minimum sample size is needed to be 90 confident that the sample mean is within 1 hour of the true population mean 20 10 20 05 20 025 20 01 20 005 1 282 1 645 1 960 2 326 2 576 Use the table above for the 2 score Round only at the final step Provide your answer below