Statistics Questions and Answers

26 Contaminated water In a sample of 42 water specimens taken from a construction site 26 contained detectable levels of lead a Construct a 90 confidence interval for the proportion of water specimens that contain detectable levels of lead b Construct a 95 confidence interval for the proportion of water specimens that contain detectable levels of lead What is the

3 pts Using StatCrunch construct a labeled contingency table with row column and total s as w as the contribution to the chi square statistic for the following set of data for 300 people Had flu shot Didn t have flu shot Total Group A 20 80 100 Group B 30 70 100 Is the value of the chi square statistically significant Group C 62 100 Total 88 212 300 1 pt Write a short paragraph summarizing the results of the analysis in Exercise 1

What s the effective annual rate EAR of a credit card that charges an annual interest rate of 18 compounded monthly Answer in percent rounded to one decimal place

3 For vector addition you have to use law O Pascal s O the parallelogram triangle O the arithmetic O Newton s Second D Question 4 Convert a length value of 63 ft into Sl units O 20 1 in O 206 69 Slug 2 5 pt 20 1 N

1 The subject of mechanics statics deals with what happens to a body when is are applied to it O a magnetic field neutrons lasers O heat O forces Question 2 2 Which one of the following is a scalar quantity O Position 2 5 pts 1

3 For vector addition you have to use law O Pascal s O the parallelogram triangle O the arithmetic O Newton s Second D Question 4 Convert a length value of 63 ft into Sl units O 20 1 in O 206 69 Slug 2 5 pt 20 1 N

Given A force acting on a pipe Find Resolve the force into components along the u and v axes and determine the magnitude of each of these components 15 Plan a Construct lines parallel to the u and v axes and form a parallelogram 30 lb 30 b Resolve the forces into their u v components C Find magnitude of the components from the law of sines NJIT

Supposed you currently have savings of 8 000 you will invest If your goal is to have 10 000 after 3 years what annual rate of return would you need to earn on your investment Answer in percentage and round to one decimal place

prives for the following time period March 2 2017 to March 16 2017 Use the last two digits for decimals of the closing price and use them to replace the X X s in the following table Notice that in the dataset a decimal point will seperate the two digits Head Width cm Biting force grams cemtimeter 2 4 31 3 92 2 56 3 72 4 21 2 95 4 74 12X X 11X X 9XX 10XX 12X X 10X X 13XX 2 84 11XX Imagine that you are examining the functional relationship between head width measured in centimeters and biting force measured in grams per square centimeter in the tegu lizard a Conduct a linear regression by hand You will need to show the slope and the intercept of the best fit line Also construct a scatterplot graph with all data points and trace the best fit line if you want you can do the graph on Excel b Conduct a hypothesis test for the significance of the slope of the best fit line ANOVA table c Calculate a 95 confidence interval for the population slope d Calculate the coefficient of determination r 2 SHOW ALL WORK AND EXPLAIN ALL RESULTS Here are my closing prices for March 2 March 16 2017 starting from March 2 and ending March 16 note yes there are a few days missing from the data and that is alright for this problem 134 50 133 65 133 33 122 28

QUESTION 1 12 MARKS a Determine the level of measurement for each of the following variables i Calculus test mark b ii Type of cuisine served at a hotel buffet ii Top 10 of Great Eastern Takaful Insurance iv Type of package offered by travel agency I The computer giant IBM has 329 373 employees and 63 133 stockholders The vice president plans to conduct a survey to study the number of shares held by individual stockholders 1 mark i If the survey is conducted by telephoning 30 randomly selected stakeholders in each of the 13 states in Malaysia what type of sampling technique is being used 1 mark 1 mark ii If a sample of 390 stockholders is obtained and the average number of shares is calculated is the result is a parameter or statistic Give your reason 2 marks 1 mark 1 mark

What is the present value of 300 to be received at the end of each year in perpetuity Assume a discount rate of 6 Round to the nearest dollar

22 11 pts Let f be a continuous function on the interval 0 x a f x dx f a x dx by the substitution rule a Show that b Explain why f a da f a 2 dz by using the Riemann sum definition limit definiti of definite integral 0 T 2 3 cos x sin x 2 F

5 a Consider two kets la and 18 Suppose a la a la and a a B are all known where la la form a complete set of base kets Find the matrix representation of the operator la B in that basis b We now consider a spin system and let la and 8 be s 2 and sx 2 respectively Write down explicitly the square matrix that corre sponds to la B in the usual s diagonal basis

What are the disadvantages of an alliance such as that made with Dynamic OA Dynamic could steal customers away OB There are no disadvantages C The alliance is just a temporary bandage to repairing Premier s supply chain D Dynamic is too powerful of a firm with which to participate

A restaurant chain has two locations in a medium sized town and believing that it has oversaturated the market for its food is considering closing one of the restaurants The manager of the restaurant with a downtown location claims that his restaurant generates more revenue than the sister restaurant by the freeway The CEO of this company wishing to test this claim randomly selects 36 monthly revenue totals for each restaurant The revenue data from the downtown restaurant have a mean of 360 000 and a standard deviation of 50 000 while the data from the restaurant by the freeway have a mean of 340 000 and a standard deviation of 40 000 Assume there is no reason to believe the population standard deviations are equal and let 1 and 22 denote the mean monthly revenue of the downtown restaurant and the restaurant by the freeway respectively Refer to Exhibit 10 3 At the 5 significance level does the evidence support the manager s claim O O No since the test statistic value is less than the critical value Yes since the test statistic value is less than the critical value No since the test statistic value is greater than the critical value Yes since the test statistic value is greater than the critical value

15 Given the graph of a function f x sketch the graph of the derivative on the axes provided 4 f x f x 3

You are still working for the chocolate company and have been transferred to the production department Upon your arrival you receive the following information There are 4 inputs in the production process capital labour raw material ingredients and energy C L R E The marginal productivity is for capital and labour 4 and 2 and is unknown for raw material and energy The marginal productivities are all constant The current level of production is at 10 000 chocolate bars per week with 100 units of capital 90 units of labour 4640 units of raw material and 430 units of energy denoted 100 90 4640 430 The price per unit of each input is 3 for capital 10 for labour 0 25 for raw material and 1 for energy c Assuming constant productivity and starting from the allocation 100 90 4640 430 it has been decided that labour would be decreased by 25 units To keep the production level unchanged energy and raw material are both increased by the same amount A What is A If needed round your answer to 2 digits after the decimal point

Question 7 Category You are conducting a multinomial Goodness of Fit hypothesis test for the claim that the 4 categories occur with the following frequencies Ho PA 0 2 PB 0 3 Pc 0 3 PD 0 2 a Complete the table Report all answers accurate to four decimal places Expected Relative Frequency A B C D Observed Frequency 21 26 28 23 b What is the chi square test statistic for this data Round your answer to 3 decimal places x c What is the p value Round your answer to 4 decimal places P Value d For significance level alpha 0 01 Expected Frequency What would be the conclusion of this hypothesis test Residual

You are conducting a Goodness of Fit hypothesis test for the claim that the 4 categories occur with the following frequencies Ho PA 0 15 PB 0 3 pc 0 4 PD 0 15 a Complete the table below Give all answers in the table as decimals rounded to 4 places after the decimal point if necessary Category A B C D Observed Frequency 9 15 46 6 Expected Relative Frequency b What is the chi square test statistic for this data Round your answer to 3 decimal places Test Statistic Expected Frequency c For a significance of level alpha 0 01 what is the chi square critical value Critical Value x d What would be the decision of this hypothesis test Reject the Null Hypothesis OFail to reject the Null Hypothesis Residual

You are conducting a multinomial hypothesis test for the claim that the 4 categories occur with the following frequencies Ho PA 0 15 PB 0 3 pc 0 15 PD 0 4 a Complete the table Round all values to 4 decimal places if necessary Category Expected Relative Frequency A B C D Observed Frequency 31 Question Help Post to forum 25 17 45 Expected Frequency b What is the chi square test statistic for this data Round your answer to 3 decimal places Residual

Question 2 Calculate the standard deviation and variance of the sample data shown to two decimal places X 24 7 22 5 16 1 11 7 21 8 14 7 14 1 Standard deviation Variance

OA Ho P1 P2 H P1 P2 OD Ho P1 A newspaper published an article about a study in which researchers subjected laboratory gloves to stress Among 222 vinyl gloves 62 leaked viruses Among 222 latex gloves 14 leaked viruses Using the accompanying display of the technology results and using a 0 05 significance level test the claim that vinyl gloves have a greater virus leak rate than latex gloves Let vinyl gloves be population 1 Click the icon to view the technology results P2 H P P2 Question 3 9 1 5 Part 2 of 4 Identify the test statistic CHEKLAD CE Ho P1 P2 H P P2 CE Ho P1 P2 H P1 P2 Round to two decimal places as needed HW Score 71 34 4 99 of 7 points Points 0 83 of 1 OC Ho P1 P2 H P P2 OF Ho P1 H P Save P2 P2

MyOpenMath The following data represents the GPA of a sample of 15 students enrolled in a math class Use technology and round to 4 decimal places GPA 2 04 2 74 2 5 2 79 1 7 3 12 3 35 2 19 3 96 2 64 2 36 1 63 2 11 3 01 3 27 a Find the first quartile 50 b Find the third quartile c Find the mean d Find the median e Find the range f Find s g Find the interquartile range h What are the lower and upper limits to find outliers

Question 15 In a mid size company the distribution of the number of phone calls answered each day by each of the 12 receptionists is bell shaped and has a mean of 55 and a standard deviation of 11 Using the empirical rule what is the approximate percentage of daily phone calls numbering between 44 and 66 Do not enter the percent symbol ans

Question 11 A political scientist surveys 23 of the current 95 representatives in a state s legislature What is the size of the sample What is the size of the

Question 5 In a study the data you collect is Wage per hour What is the level of measurement O nominal O ordinal O interval

5 6 7 8 9 10 11 12 13 14 15 16 17 18 data Q Based on the boxplot above identify the 5 number summary 0 0 0 0 0

In a dataset of 7 607 men and women with HIV using a simple linear regression the relationship between CD4 count and AGE is presented below Calculate the predicted CD4 value for a 22 year old person YOU MUST SHOW YOUR WORK FOR THIS QUESTION Model 1 Coefficientsa Unstandardized Coefficients B Std Error Constant 346 793 AGE 2 852 a Dependent Variable CD4 LAST 17 471 473 Standardized Coefficients Beta 069 Sig 19 850 001 6 031 001

Multiple Choice questions in myomlab provide four or five possible answers to a question The possible answers are often labeled A B C etc To select an answer click on the radio button beside the answer you wish to choose and then click the Check Answer button in the lower right hand corner of the window Question How many inches are in one foot A 15 B 10 C 12 D 24 Sometimes a single question will include multiple parts like this question and you must answer all parts to receive fu credit The next three parts of this exercise will give you some experience with answering other types of questions in myomlab Fill in the blank Some questions require you to answer a fill in the blank question by choosing one of several possible answers provided in a drop down box Select an answer and click Check Answer to go to the next part Part 1 complete the statement There are innings in a typical baseball game nine eight twelve

5 P Determine the minimum horizontal force P required to hold the crate from sliding down the plane The crate has a weight of 500 lb and the coefficient of static friction between the crate and the plane is us 0 35 30

You are hired by a big chocolate company which produces chocolate for runners called TobbyRun and you are asked to find the optimal packaging for the best selling product The shape of the product is the following h h h k The triangle in front and behind the image must be the same equilateral triangle The packaging is fully closed On top of this 10 of the volume of the box must be empty must not contain chocolate Each packaging will contain chocolate weighing 200 grams The density of chocolate is 1 2gram cm c The production line finally tells you they need a packaging with a volume of 220cm Assuming you want to create the packaging using the smallest amount of cardboard possible while still satisfying the constraint what are the values of k in cm If needed round your answer to 2 digits after the decimal point

Home Sales Prices hundred thousands ten thousands 667778999 0 1 2 3 02447778889999 0011234445667889 00011224 The stem and leaf plot above shows house sale prices over the last week in Tacoma What was the most expensive house sold Give your answer in dollars

The IQ scores of 50 students are given below 115 111 92 108 99 116 108 114 90 112 95 93 115 97 108 97 97 103 85 107 113 102 117 103 118 112 100 94 85 105 113 92 105 108 99 101 91 85 104 89 89 108 111 88 108 86 104 110 114 91 a Construct a grouped frequency distribution for the data Use 85 89 for the first class and use the same width for each subsequent class Class Frequency 85 89 0 010 b Which of the following is the correct histogram for this data Frequency 8 6 4

Using the following stem leaf plot find the five number summary for the data by hand 1 13 21566 3156 411229 5115789 6133 Min Q1 Med Q3

In a student survey fifty two part time students were asked how many courses they were taking this term The incomplete results are shown below Please round your answer to 4 decimal places for the Relative Frequency if possible of Courses Frequency Relative Frequency Cumulative Frequency 1 10 2 3 21 Submit Question 0 4038 0 4038 What percent of students take exactly two courses Frequency Tables 10 31 1

50 part time students were asked how many courses they were taking this term The incomplete results are shown below of Courses Frequency Relative Frequency Cumulative Frequency 1 2 3 15 14 0 3 a Complete the table b What percent of students take exactly three courses Hint Submit Question

70 adults with gum disease were asked the number of times per week they used to floss before their diagnoses The incomplete results are shown below of times floss per week Frequency 0 1 2 3 4 5 6 7 7 10 Relative Frequency 0 1 0 1 10 5 11 15 5 a Complete the table Use 4 decimal places when applicable b What is the cumulative relative frequency for flossing 2 times per week 0 1429 0 0714 0 1571 0 2143 0 0714 Cumulative Frequency 7 14 24 39 50 65 70

Question 2 2 210 people are asked how many siblings they have of Siblings Frequency Relative Frequency Cumulative Frequency 0 41 1 35 0 1667 0 2381 0 1952 0 2048 41 76 126 3 41 4 43 a Complete the table Use 4 decimal places when applicable b What percent of the people have exactly one sibling Frequency Tables 210

Core 0 7 0 7 answered Question 1 Y Data was collected for 300 fish from the North Atlantic The length of the fish in mm is summarized in the GFDT below Lower Class Boundary Lengths mm Frequency 180 199 1 200 219 16 220 239 71 240 259 108 260 279 83 280 299 18 300 319 3 What is the lower class boundary for the first class class boundary Submit Question

Find the least squares cubic equation that best fits the points 2 2 1 1 0 1 1 2 2 2

The city of Cleansburg has 9076 registered voters There is an election for Mayor of Cleansburg and there are three candidates for the position Smith Jones and Brown The day before the election a telephone poll of 930 randomly chosen registered voters produced the following results 243 people surveyed indicated that they would vote for Smith 613 indicated that they would vote for Jones and 74 indicated that they would vote for Brown a Give the sampling proportion for this survey Round the answer to two decimal places b Give the sample statistic estimating the percentage of the vote going to Smith Round the answer to two decimal places

4 Starting with a random matrix A R100x100 perform QR iteration 200 times Plot the sparsity pattern for initial matrix A and final output matrix

Students in an experimental psychology dass did research on depression as a sign of stress A test was administered to a sample of 30 students The scores are shown below 44 51 11 91 77 38 84 37 43 72 53 62 36 75 51 72 37 28 28 61 48 63 38 41 22 37 51 46 88 14 To find the 10 trimmed mean of a data set order the data delete the lowest 10 of the entries and the highest 10 of the entries and find the mean of the remaining entries Complete parts a through c a Find the 10 trimmed mean for the data The 10 trimmed mean is Round to the nearest tenth as needed b Compare the four measures of central tendency including the midrange Mean Round to the nearest tenth as needed Median Mode Use a comma to separate answers as needed The midrange is found by the following formula Maximum data entry Minimum data entry 2 Midranand in the nearest tenth oe needed Next

Assume that a randomly selected subject is given a bone density test Those test scores are normally distributed with a mean of 0 and a standard deviation of 1 Find the probability that a given score is between 2 03 and 3 61 and draw a sketch of the region Sketch the region Choose the correct graph below CA Q A 2 03 3 61 The probability is Round to four decimal places as needed OB 2 03 3 61 GECED OC 2 03 3 61 D 2 03 3 61

withdrawal occurs when a person who uses alcohol excessively suddenly stops the alcol s have shown that the onset of withdrawal is experienced a mean of 39 5 hours after the with a standard deviation of 19 hours A sample of 40 people who use alcohol excessively What is the probability that the sample mean time between the last drink and the onset awal will be 40 2 hours or less your intermediate computations to at least four decimal places Round your answer to at decimal places

Let Z be a standard normal random variable Calculate the following probabilities using the ALEKS calculator Round your responses to at least three decimal places P Z 0 80 P Z 0 73 P 0 46 Z 2 15

A real number between 0 and 10 will be picked according to the probability distribution shown in figure Regions under the curve are labeled with A B C and D The area of each region is shown in the tab 0 1 2 B 3 4 50 6 7 D 8 Use the figure and the table to answer the parts below 9 10 11 a Find the probability that a real number between 0 and 4 is picked b Find the probability that a real number between 2 and 7 is picked Region A B C D Area 0 10 0 30 0 45 0 15

Suppose that the antenna lengths of woodlice are approximately normally distributed with a mean of 0 2 inches and a standard deviation of 0 05 inches What proportion of woodlice have antenna lengths that are more than 0 23 inches Round your answer to at least four decimal places

Let Z be a standard normal random variable Use the calculator provided or a standard normal table to determine the value of c P Z c 0 2296 Carry your intermediate computations to at least four decimal places Round your answer to two decimal places

Set up the volume of revolution about the line y 4 of the region between the curve y 1 2 x 9 and the curve y 1 2x 2 5x 9 a Use the method of washers b Use the method of shells