Statistics Questions

Calculate the standard score z score of the given sample mean Round your answer to two decimal places 28 and G 8 n 67 3 27 Answer

The mean per capita consumption of milk per year is 126 liters with a standard deviation of 24 liters If a sample of 100 people is randomly selected what is the probability that the sample mean would be less than 122 27 liters Round your answer to four decimal places Answer Tables Keypad

A production manager at a wall clock company wants to test their new wall clocks The designer claims they have a mean life of 18 years with a standard deviation of 4 years If the claim is true in a sample of 49 wall clocks what is the probability that the mean clock life would be greater than 18 8 years Round your answer to four decimal places Answer Tables Keypad

The mean life of a television set is 123 months with a standard deviation of 19 months If a sample of 55 televisions is randomly selected what is the probability that the sample mean would be less than 121 8 months Round your answer to four decimal places Answer How to enter your answer opens in new window Tables Keypad Keyboard Shortcuts

Following are the ages of the winners of the men s Wimbledon tennis championship and the Masters golf championship for selected years Construct back to back split stem and leaf plots for these data sets in which each stem appears twice once for leaves 0 4 and again for leaves 5 9 Do not separate the answers with commas If there are no leaves on a particular stem select the None button Wimbledon 1 1 22 Masters Ages of Wimbledon Winners 23 23 22 24 27 24 31 27 26 22 25 24 23 21 25 21 22 17 20 21 22 24 30 26 21 25 29 29 30 26 35 23 31 Ages of Masters Winners 36 33 43 32 33 39 27 38 33 33 29 39 38 39 28 38 32 31 25 29 33 26 23 26 27 Send data to Excel 28 46

The mean number of words per minute WPM typed by a speed typist is 79 with a variance of 225 What is the probability that the sample mean would be greater than 76 6 WPM if 97 speed typists are randomly selected Round your answer to four decimal pl Answer How to enter your answer opens in new window Tables Uit Kevyhnards

The mean weight of an adult is 79 kilograms with a standard deviation of 10 kilograms if 188 adults are randomly selected what is the probability that the sample mean would be greater than 80 5 kilograms Round your answer to four decimal place Answer Tables

Suppose that a study of elementary school students reports that the mean age at which children begin reading is 5 5 years with a standard deviation of 1 0 years Step 1 of 2 If a sampling distribution is created using samples of the ages at which 46 children begin reading what would be the mean of the sampling distribution of sample means Round to two decimal places if necessary Answer Keypad Keyboard Shortcuts Tables

A study on the latest fad diet claimed that the amounts of weight lost by all people on this diet had a mean of 23 9 pounds and a standard deviation of 7 3 pounds Step 1 of 2 If a sampling distribution is created using samples of the amounts of weight lost by 58 people on this diet what would be the mean of the sampling distribution of sample means Round to two decimal places if necessary Answer Tables Keypa Keyboard Shortc

Find the standard deviation of the sampling distribution of sample means using the given information Round to one decimal place if necess W 42 and 0 n 25 Answer

Find the mean of the sampling distribution of sample means using the given information Round to one decimal place if necessary 55 and o 10 n 4 Answer

ide if the statement is True or False swer A sampling distribution of sample means has a mean equal to the population mean p False True

a normal approximation be used for a sampling distribution of sample means from a population with 53 and 9 when n 64 wer O Yes because the mean is greater than 30 O No because the sample size is more than 30 O No because the standard deviation is too small Yes because the sample size is at least 30 Table

The geyser Old Faithful in Yellowstone National Park alternates periods of eruption which typically last from 1 5 to 4 minutes with periods of dormancy which are considerably longer The following table presents the durations in minutes of 30 dormancy periods that occurred during a recent year 90 92 66 89 98 89 97 99 90 88 83 90 116 101 66 86 83 97 82 82 Part 0 2 71 Send data to Excel Part 1 of 2 91 00 99 82 96 91 61 97 92 59 a Construct a frequency distribution using a class width of 5 and using 55 as the lower class limit for the first class Dormancy Period Frequency

Given the building layout for Store A Store B Store C and Store D what portion of the share 7500 maintenance costs should be apportione to Store D A 2500ft B C D 1250 ft 625 ft 625 ft apportioned cost Round you answer to the nearest hundredth

0 9999451342 5 460398688 x 10 5 Keep working At least one of the answers above is NOT correct Getting things wrong is part of learning 0 9999451342 5 460398688E 05 1 point 456 and standard The Graduate Record Examination is built on the following two distributions the verbal part is normally distributed with mean deviation 120 and the quantitative reasoning part is normally distributed with mean 586 and standard deviation 149 Use this information to compute the following a Compute the score of a student who scored in the 80th percentile on the quantitative reasoning section b Compute the score of a student who scored worse than 70 of the test takers in the verbal reasoning section Keep Working Keep Working Note You can earn partial credit on this pmblem

In a certain college 38 of the physics majors belong to ethnic minorities If 20 students are selected at random from the physics majors what is the probability that less than 7 belong to an ethnic minority 0 755 0 312 0 489 0 511

Using the information from the two previous problems would it be unusual if one of these students had 14 correct answers on the quiz Yes No

Several students are unprepared for a multiple choice quiz with 44 questions and all their answers are guesses Each question has four possible answers and only one of them is correct Find the mean number of correct answers for such students

Is the binomial distribution appropriate for the following situation Ask 125 randomly selected U S citizens if they have ever visited London England X is the number that say yes Yes No

According to the National Student Clearinghouse Research Center women now comprise 60 of enrollment in universities What is the probability in a random sample of 55 university students that more than 35 are women Round your answer to 3 decimal places

In the United States 41 of 18 to 29 year olds said in a survey held in March 2020 that they currently subscribed to Hulu What is the probability in a random sample of 75 18 to 29 year olds that 35 will say they currently have a subscription to Hulu 0 811 0 056 0 103 0 867

Write a statement explaining what the probability means in the previous problem

According to Gallup 48 9 of the U S are protestant A random sample of 40 U S residents is selected They find that 18 of the residents are protestant Identify n p and x n p X A A

Physicians and pharmacists sometimes fail to inform patients adequately about the proper application of prescription drugs and about the precautions to take in order to avoid potential side effects One method of increasing patients awareness of the problem is for physicians to provide Patient Medication Instruction PMI sheets The American Medical Association however has found that only 25 of the doctors who prescribe drugs frequently distribute PMI sheets to their patients The probability that a randomly selected patient will be hospitalized for a drug related problem given that the person has received the PMI sheet is 32 where as the probability that a randomly selected patient will be hospitalized for a drug related problem given that the person has not received the PMI sheet is 72 A patient is randomly selected Find the probability that the patient received the PMI sheet and was not hospitalized for a drug related problem a 27 31 b 17 100 c 19 50 Od 17 31 e 17 38

The Value Line Survey a service for common stock investors provides its subscribers with up to date evaluations of the prospects and risks associated with the purchase of a large number of stocks Each stock is ranked 1 highest to 5 lowest according to Value Line s estimate of the stock s potential for price appreciation during the next 12 months Suppose you plan to purchase stock in three electrical utility companies from among eight that possess rankings of 2 for price appreciation Unknown to you two of the companies will experience serious difficulties with their nuclear facilities during the coming year If you randomly select the three companies from among the eight what is the probability that you select one of the companies with prospective nuclear difficulties a 15 28 b 3 28 c 3 14 d 5 14 e 9 14

Let A and B be two events with P A and BC 1 Find P B Recall that BC denotes the complement of the event B O a 1 Ob 0 75 O c 0 5 Od 0 25 O e 0

Are black defendants in a murder trial more likely to get the death penalty when the victim is white The table below shows the outcome whether the death penalty is imposed or not of murder trials in Florida betwee 1976 and 1987 Death Penalty Imposed Death Penalty not Imposed Defendant White Victim Black Victim White Victim Black Victim 414 16 37 139 White 53 Black 11 0 4 One defendant is selected at random If the selected defendant is black what is the probability that the defendant got the death penalty a 0 028 b 0 0785 c 0 2292 d 0 1135

Harold and Maude plan to take a cruise that departs from Miami together but they live in separate cities Based on their itinerary to Miami Harold s chance of making it to the cruise is 87 whereas Maude s is 91 Assume that the event of Harold making it is independent of the event of Maude making it What is the probability that only Harold makes it to the cruise a 0 87 b 0 91 c 0 0117 d 0 0783 e 0 3983

O Macmillan Learning How old are women when they have their first child The table displays the distribution of the age of the mother for all firstborn children in the United States in 2017 Age Count Age Count 10 14 years 1 892 30 34 years 329 623 15 19 years 162 536 35 39 years 124 637 20 24 years 395 927 40 44 years 24 049 25 29 years 417 162 45 49 years 2 377 The number of firstborn children to mothers under 10 or over 50 years of age represent a negligible percentage of all first births and are not included in the table In which age classes do the median and quartiles fall Be sure to give all three values before checking your answer Q median Q3 45 49 years 35 39 years 30 34 years 10 14 years Answer Bank 20 24 years 30 34 years 40 44 years 15 19 years 25 29 years 35 39 years 45 49 years

Horchata 56 Jamaica Carne Al Asada Pastor Totals 0 Tamarindo 7 63 9 6 33 48 Lengua Totals 8 29 12 49 73 35 52 160 The table above lists the preference of tacos and drink combinations for people What s th probability that a person likes horchata or tacos de al pastor You can write your answer a decimal rounded to 4 places or a percent don t include in answer

A company manufactures batteries in batches of 24 and there is a 3 rate of defects Find the mean number of defects per batch O 23 28 O 0 744 O 0 696

Find the indicated probability A company purchases shipments of machine components and uses this acceptance sampling plan Randomiy select and test 20 components and accept the whole batch if there are fewer than 3 defectives If a particular shipment of thousands of components actually has a 8 rate of defects what is the probability that this whole shipment will be accepted O 0 5993 O 0 2711

ne problem The probability that a radish seed will germinate is 0 7 A gardener plants seeds in batches of 13 Find the standard deviation for the number of seeds germinating in each batch O 1 587 O 1 632

Use the given values of n and p to find the minimum usual value 2o and the maximum usual value u 20 1130 p 0 94 n O Minimum 1078 17 maximum 1046 23 O Minimum 1046 23 maximum 1078 17 O Minimum 1050 91 maximum 1073 49 O Minimum 1054 22 maximum 1070 18

Determine if the outcome is unusual Consider as unusual any result that differs from the mean by more than 2 standard deviations That is unusual values are either less than 20 or greater than 26 A survey for brand recognition is done and it is determined that 68 of consumers have heard of Dull Computer Company A survey of 800 randomly selected consumers is to be conducted For such groups of 800 would it be unusual to get 625 consumers who recognize the Dull Computer Company name O Yes O No

Find the indicated probability An airline estimates that 91 of people booked on their flights actually show up If the airline books 79 people on a flight for which the maximum number is 77 what is the probability that the number of people who show up will exceed the capacity of the plane O 0 0045 O 0 0051 O 0 0006

Find the mean of the given probability distribution The accompanying table shows the probability distribution for x the number that shows up when a loaded die is rolled Probability For a Loaded Die When Rolled O 3 50 O 0 17 O 4 01 O4 14 X 1 2 3 4 5 96 P x 0 11 0 13 0 13 0 14 0 12 0 37

Suppose that voting in municipal elections is being studied and that the accompanying table describes the probability distribution for four randomly selected people where x is the number that voted in the last election Is it unusual to find four voters among four randomly selected people Probability of Four People Voting XO234 1 P x 0 23 0 32 0 26 0 15 0 04

Find the indicated probability What is the probability that 4 rolls of a fair die will show exactly three fours O 0 0116 0 0039

It is believed that Lake Tahoe Community College LTCC Intermediate Algebra students get less than seven hours of sleep per night on average A survey of 22 LTCC Intermediate Algebra students generated a mean of 7 24 hours with a standard deviation of 1 93 hours At a level of significance of 5 do LTCC Intermediate Algebra students get less than seven hours of sleep per night on average Fill in the blank The Type Il error is not to reject that the mean number of hours of sleep LTCC students get per night is at least seven when in fact the mean number of hours Note at most means less than or equal to at least means greater than or equal to is more than seven hours is at most seven hours is at least seven hours

A company surveyed 32 male employees on their weight and the number of hours they were active every day The following scatterplot has a linear model and coefficient of determination Question 7 of 12 Weight in Pounds NO f x 9 6 x 205 54 0 76 200 190 180 170 160 150 140 130 120 Number of Hours Active Per Day 2018 WGU Powered by GeoGebra 12 Which statement about this regression is correct To answer the question of how many hours a man should be active to maintain a weight of 170 pounds use an interpolation and extrapolation value O To answer the question of how many hours a man should be active to maintain a weight of 170 pounds use an extrapolation value O To answer the question of how many hours a man should be active to maintain a weight of 170 pounds use the regression s coefficient of determination O To answer the question of how many hours a man should be active to maintain a weight of 179 pounds use an interpolation

Question 6 of 12 7 000 6 000 5 000 4 000 3 000 2000 1 000 0 Number of Gamers Per Day Which statement is true about this regression ng linear regression 0 96 f x 537 85x 801 42 Number of Days Since January 1 10 14 16 O 2018 WGU Powered by GeoGebra O By f 1 1 854 there was approximately 1 854 gamers on December 31 By f 15 6 600 there would be approximately 6 600 gamers on January 15 OA logistic regression should be used instead of a linear regression By the very good coefficient of determination a lin

A normal distribution has a standard deviation of 1 We want to verify a claim that the mean is greater than 12 A sample of 36 is taken with a sample mean of 12 5 Calculate the test statistic T S

When a new drug is created the pharmaceutical company must subject it to testing before receiving the necessary permission from the Food and Drug Administration FDA to market the drug Suppose the null hypothesis is the drug is unsafe What is the Type II Error To conclude the drug is safe when in fact it is unsafe Not to conclude the drug is safe when in fact it is safe O To conclude the drug is safe when in fact it is safe O Not to conclude the drug is unsafe when in fact it is unsafe

We want to test whether the mean GPA of students in American colleges is different from 2 0 out of 4 0 The null and alternative hypotheses are 1 Ho 2 Ha 1 HO 2 Ha 2 0 2 0 Choose O Choose

We want to test if it takes fewer than 45 minutes to teach a lesson plan State the null and alternative hypotheses Match the correct symbol for the null and alternative hypotheses 1 Ho 2 Ha 1 HO 2 Ha 45 45 V Choose Choose

Jeffrey as an eight year old established a mean time of 16 43 seconds for swimming the 25 yard freestyle with a standard deviation of 0 8 seconds His dad Frank thought that Jeffrey could swim the 25 yard freestyle faster using goggles Frank bought Jeffrey a new pair of expensive goggles and timed Jeffrey for 15 25 yard freestyle swims For the 15 swims Jeffrey s mean time was 16 seconds Frank thought that the goggles helped Jeffrey to swim faster than the 16 43 seconds Calculate the test statistic T S Use 2 decimal places

Question 4 of 12 30 25 20 451 Population in Thousands 10 f x 2 386 Which statement is true about this regression 0 72 Number of Years Since 1900 25 30 35 40 45 50 55 60 65 2018 WGU Powered by GeoGebra O Investigate the possible outlier before drawing any conclusion O By 65 22 2 on the function it can be estimated that the town s population was approximately 22 200 in 1965 This is an interpolation By 65 22 2 on the function it can be estimated that the town s population was approximately 22 200 in 1965 This is an extrapolation O A linear regression should be used before drawing any conclusion

1 Assume HO 9 and Ha u 9 2 Assume HO u s 6 and Ha 6 3 Your friend claims that his mean golf score is 63 4 You flip a coin and record whether it shows heads or tails You know the probability of getting heads is 50 but you think it is less for this particular coin 5 Your friend claims that his mean golf score is 63 You want to show that it is Choose O Choose Choose Choose Choose