Statistics Questions and Answers

4 Bill is offering Internet training in his home This graph represents the number of students he met with daily during two separate weekly periods Examine the graph and answer the questions that follow Students 10 8 9 4 2 O Mon Tues Wed Thurs Fri Sat Sun 5 marks Week 1 Week 2

Evaluate the following formula for p 0 8 p 05 P P 0 p 0 089824 6 0 910376 49 and Z z Round to two decimal places as needed

Evaluate E T t Sd for t 0 673 s 3 151 and n 8 n Pound

The South Division of Wiig Company reported the following data for the current year Sales Variable costs Controllable fixed costs Average operating assets Top management is unhappy with the investment center s return on investment ROI It asks the manager of the South Division to submit plans to improve ROI in the next year The manager believes it is feasible to consider the following independent courses of action 1 2 3 Increase sales by 300 000 with no change in the contribution margin percentage Reduce variable costs by 155 000 Reduce average operating assets by 496 3 050 000 2 013 000 600 000 5 000 000 a Compute the return on investment ROI for the current year Round ROI to 2 decimal places e g 1 57 Return on Investment Action 1 b Using the ROI formula compute the ROI under each of the proposed courses of action Round ROI to 2 decimal places eg 1 57 Action 2 Return on investment R 96 96 96

Appliance Possible Inc AP is a manufacturer of toaster ovens To improve control over operations the president of AP wants to begin using a flexible budgeting system rather than use only the current master budget The following data are available for AP s expected costs at production levels of 82 000 96 000 and 110 000 units Variable costs Manufacturing Administrative Selling Fixed costs Manufacturing Administrative a 7 per unit 4 per unit 1 per unit 160 000 79 000 Prepare a flexible budget for each of the possible production levels 82 000 96 000 and 110 000 units List variable costs before fixed costs APPLIANCE POSSIBLE INC Flexible Production Cost Budget

this problem Find the slope of the line shown on the graph to the right Select the correct choice below and if necessary fill in the answer box to complete your choice OA The slope of the line is Simplify your answer Type an integer or a fraction OB The slope is undefined 2 6 6 10

In each case determine the value of the constant c that makes the probability statement correct Round your answers to two decimal places USE SALT a c 0 9854 b P 0 Z c 0 3133 c P CZ 0 1357 d P cs Zsc 0 6424 e P cs 21 0 0128

An article suggests the uniform distribution on the interval 8 5 22 as a model for depth cm of the bioturbation layer in sediment in a certain region a What are the mean and variance of depth Round your variance to two decimal places mean variance b What is the cdf of depth 0 m f F x 1 x 8 5 8 5 x 22 22 5 x c What is the probability that observed depth is at most 10 Round your answer to four decimal places What is the probability that observed depth is between 10 and 15 Round your answer to four decimal places d What is the probability that the observed depth is within 1 standard deviation of the mean value Round your answer to four decimal places What is the probability that the observed depth is within 2 standard deviations of the mean value

The defect length of a corrosion defect in a pressurized steel pipe is normally distributed with mean value 31 mm and standard deviation 7 7 mm USE SALT a What is the probability that defect length is at most 20 mm Less than 20 mm Round your answers to four decimal places at most 20mm less than 20mm b What is the 75th percentile of the defect length distribution that is the value that separates the smallest 75 of all lengths from the largest 25 Round your answer to four decimal place mm c What is the 15th percentile of the defect length distribution Round your answer to four decimal places mm d What values separate the middle 80 of the defect length distribution from the smallest 10 and the largest 10 Round your answers to four decimal places smallest 10 largest 10 mm mm

A monopolist faces the following demand curve Price 51 47 42 36 29 21 12 4 units 5 units Quantity 3 units 2 13 5 Refer to Table 15 5 The monopolist has total fixed costs of 60 and has a constant marginal cost of 15 Wha profit maximizing level of production 6 7

Quantity 4 3 units 4 units 6 units Price 5 units 20 18 16 14 Suppose marginal cost is constant at 8 per unit The firm depicted in the table is selling a prescription drug for whi it had a patent but the patent has expired As new firms enter the market and sell the generic version of this drug competitively what quantity will be sold 12 10 8

Let X be a continuous rv with the following cdf 0 x 50 0 x 7 F x X 7 This type of cdf is suggested in the article Variability in Measured Bedload Transport Rates as a model for a certain hydrologic variable a What is P X 2 Round your answer to three decimal places b What is P 2 s X s 6 Round your answer to three decimal places c What is the pdf of X

If the temperature at which a certain compound melts is a random variable with mean value 125 C and standard deviation 6 C what are the mean temperature and standard deviation measured in F Hint F 1 8 C 32 mean standard deviation OF F

4 The average IQ of 48 month old girls is 108 A random sample of 30 adopted girls was found to have a mean IQ of 103 with a standard deviation of 18 Is it reasonable to conclude that the mean IQ of adopted girls is different from that of the general population of 48 month old girls Please answer the question by providing a two hypotheses along with assumptions b significance level use 0 05 level c critical values with appropriate df d decision rules e computations and f decision and interpretation

3 The average IQ of male students at State Universities in the U S is reported to be 111 A random sample of 49 male students who were the firstborn children in their families was found to have a rtean IQ of 116 with a standard deviation of 14 Can you conclude that firstborn male students have a different IQ from that of the general population of male students at State Universities in the U S Please answer the question by providing a two hypotheses along with assumptions b significance level use 0 05 level c critical values with appropriate df d decision rules e computations and f decision and interpretation riate df d decision

Graph the function Be su 8 n x 2 X

1 2 3 1 x 4 4 MOL TOE 01 5 Graph the function by using transformations of the graph points on each side 8 x

Evaluate the following formula for p P 0 p 0 159247 q 1 p x 74 x 19 n 287 X1 n 297 P and P Z Z 1 n P1 P P P2 p q n X2 p q n n Round to two decimal places as needed

Evaluate p X1 X2 n n for x 27 x 1 n 49 and n 66 p Round to four decimal places as needed

Evaluate the following formula for p 0 6 p 0 5 P P 0 p 0 916841 q 0 083159 n 41 anc n 57 Z Z P P P P pq pq n n Round to two decimal places as needed

Which situation is an example of confirmation bias A coach recruits a player he believes is excellent at stealing bases because he is on a high school track team The player has made two of the last ten steal attempts The coach has the player attempt to steal the base A coach recruits a player he believes is excellent at stealing bases because he is on a high school track team The player has made eight of the last ten steal attempts The coach has the player attempt to steal the base A coach recruits a player he believes is excellent at stealing bases because he is on a high school track team The player has made nine of the last ten steal attempts The coach has the player attempt to steal the base A coach recruits a player he believes is excellent at stealing bases because he is on a high school track team Bases are loaded The coach has the player attempt to steal the base

A hockey team is losing by one with one minute to go If the coach pulls the goalie there s a 60 chance the team will score Should the coach pull the goalie Yes 60 is greater than 50 so there is a greater chance that the team will score if the coach pulls the goalie Yes 60 is greater than 50 so there is a lesser chance that the team will score if the coach pulls the goalie No 60 is greater than 50 so there is a lesser chance that the team will score if the coach pulls the goalie O No 60 is greater than 50 so there is a greater chance that the team will score if the coach pulls the goalie

Let 0 333 p 0 777 represent an interval on the number line Complete parts a and b below www a Find the value that is in the middle of the interval The value is 0 555 Type an integer or a decimal Do not round b Find the distance from the middle of the interval to either endpoint The distance is Type an integer or a decimal Do not round

If given just this information what would the government be able to calculate Geography Population per square mile 2010 87 4 Land area in square miles 2010 OU S population O rural and urban populations O mainland U S population 3 531 905 43

The following information would be most useful to which of the following agencies Health With a disability under age 65 years percent 2012 2016 Persons without health insurance under age 65 years percent 10 1 Department of Transportation Department of Commerce Department of Education A 8 6

A corporation creates a sinking fund in order to have 450 000 to replace some machinery in 10 years How much should be placed in this account at the end of each quarter if the annual interest r is 7 8 compounded quarterly Round your answers to the nearest cent How much interest would they earn over the life of the account Determine the value of the fund after 2 4 and 6 years 2 years 4 years 6 years How much interest was earned during the fourth quarter of the 4th year

The table below shows the calories of a hamburger at a fast food chain over the years Find the line of best Oy 18 252 36 240 y 18 25x 36 240 y 3 2x 6 237 y 3 2x6 237 Year Calories 2000 300 2004 320 2008 360 2012 2016 450 600

The table below represents the change in calories of a muffin over the years Find the line of best fit Year Calories 50 1970 60 1980 Oy 3 226 237 Oy 6 237x 0 9209 Oy 3 21z 259 Oy 1 21x 259 1960 1990 2000 85 120 180

e National Center for Health Statistics published the results of a national health survey from 1960 to 1962 Use the 6 99 7 normal distribution curve to find the percentage of women age 35 to 44 have cholesterol level between 171 3 d 261 9 Age 18 to 24 25 to 34 35 to 44 45 to 54 55 to 64 65 to 74 75 to 79 Women strong Mean Standard Deviation Mean Standard Deviation 178 1 184 7 197 9 216 6 205 9 226 8 30 5 232 8 229 5 224 5 Men 40 7 44 6 49 4 45 6 49 0 47 3 48 7 236 8 262 3 265 7 245 3 47 9 41 9 45 3 50 0 63 0 58 8 65 7

A group of researchers measured the cholesterol level of middle aged people in Iran They investigated possible relationships between age cholesterol level activity and body mass index BMI The low activity group had a cholesterol level of 205 1 mg dl The high activity group had a mean cholesterol level of 190 2 mg dl Which statement below is a plausible interpretation of their findings There is a negative correlation between activity and cholesterol leves O There is a positive correlation between activity and cholesterol level There is no significant correlation between activity and cholesterol level There is not enough Information to determine whether or not a correlation exists

The National Center for Health Statistics published the results of a national health survey from 1960 to 1962 The results are shown in the table below Which of the statements below is true Men Age Women Mean Standard Deviation Mean Standard Deviation 18 to 24 178 1 25 to 34 205 9 35 to 44 226 8 45 to 54 230 5 55 to 64 232 8 65 to 74 229 5 75 to 79 224 5 40 7 44 6 49 4 45 6 49 0 47 3 48 7 184 7 197 9 216 6 236 8 262 3 265 7 245 3 47 9 41 9 45 3 50 0 63 0 58 8 65 7 The variation in cholesterol for women is greatest for those aged 75 to 79 The variation in cholesterol for women is greatest for those aged 64 to 74 The variation in cholesterol for men is greater than the variation in cholesterol for women The variation in cholesterol for men aged 55 to 64 is greater than the variation for women of the same age

CONTENTS Section 4 An Extended Exploration k variance because the variance is approximately average squared difference between values and m The formula for o wolves absent is sum of squared differences na 1 Here na is the number of moose sampled from the population with wolor phoopt

Which of the following illustrates the gender wage problem A business decides to hire more men to better appeal to its client base OA man is hired for a job for which a female applicant is equally qualified A firm issues a call for female applicants to a job currently held by a retiring man O A woman has to negotiate for a salary automatically granted to male employees

The graph below shows the percentages of the population over sixty five in each county What percent of the population would you expect to have either less than 6 or more than 30 of the population over sixty five 68 95 99 7 30 20 0 6 2018 Glyntyon Inc 68 95 99 7 A H 0 20 p 30 30 Standard deviations 10 14 18 22 265

A letter home to the parents of seniors at Westgate High School says a simple random sample of 30 Westgate seniors that took the SAT M test this year produced a mean of 512 and a standard deviation of 95 A confidence interval for the true mean for all WHS seniors is 512 00 47 8 The confidence level for this interval is

In 1940 there were 1 211 684 males born and 1 148 715 females born What is the ratio of males to females 01 055 62 969 0 948 1 505

From experience an airline knows that only 80 of the passengers booked for a certain flight actually show up If 9 passengers are randomly selected find the probability that more than 6 of them show up Carry your intermediate computations to at least four decimal places and round your answer to two decimal places If necessary consult a list of formulas

Which of the following best describes a case in which the variables being studied are themselves affected by discrimination O A company s clients are primarily white males who dislike working with women and people of color An HR representative makes a practice of offering female candidates for jobs less than male candidates OA restaurant hires both female and male wait staff but the female wait staff make more in tips than the males do OA spa hires more women than men as employees because the majority of their clientele requests female therapists

Which of the following are factors for which researchers should control studies about the gender wage question Select all that apply education work experience maternity leave starting salary field of work

A study of men and women s salaries in which the significance level is 0 05 finds that 100 male college graduates earn more than 100 female high school graduates with p 0 01 This study is most open to criticism in which of the following areas Op values O sample size O population O significance level

If as Blau and Khan have argued 41 of the gender wage gap cannot be attributed to education experience industries occupations and union status we can infer that it is most likely due to which of the following O age Orace O field of work

A luxury car company makes only a few cars a month In the first six months of this year they make 6 5 6 7 9 6 cars Which of the following is the appropriate point estimate for how many cars they produce in a month a mean of 6 5 cars per month a median of 6 cars per month O a mean of 6 cars per month a median of 6 5 cars per month

Many studies submitted for publication as articles in journals are peer reviewed When a study is peer reviewed it is evaluated by a team of professionals working in the same field Critique the following studies Which study has mostly likely been peer reviewed You conduct a study and ask your classmates to review your paper before submitting it in to the teacher You conduct a study and ask your teacher to review your paper before submitting to a journal for publication You conduct a study and submit it to a journal for review You conduct a study and ask your librarian to review your paper before submitting to a journal for publication

Which is an example of a longitudinal study A researcher samples a population and assigns one group to stop smoking another group to exercise A researcher samples a population and assigns one group to exercise and one group to no exercise O A researcher samples a population of cancer survivors and studies the long term effect of exercise on health benefits OA researcher samples a population of cancer survivors who smoke and assigns one group to stop smoking and checks the 5 year survival rate

Which of the following factors may negatively impact the results of a longitudinal study Select all that apply death of participants accuracy in observing changes availability of participants ability to show patterns over time onsure focus and validity

Identify the elements of a longitudinal study Select all that apply observational research method long term study experimental research method short term study controlled conditions applies treatment

A team of researchers identified a sample of the general population for a study that began an exercise program to determine health benefits of exercise for cancer survivors What is a possible issue with a conclusion of this study stating that exercise improves health benefits for cancer survivors There is no correlation between exercise and cancer The researchers assumed that exercise is associated with cancer risk O Cancer survivors do not exercise The sample may not have included cancer survivors

Consider the Cancer Risk Factor Chart Which reasons critique the author s focus on cancer and exercise Select all that apply 25 20 15 10 5 0 3 0 Individual Risk Factor Contributions to Cancer Mortality Worldwide Alcohol Use 21 0 5 0 Smoking 0 5 1 0 Low Fruit and Vegetable Consumption Indoor Smoke Urban from Air Fossil Pollution Obesity Fuels Data source Wederpass E Lifestyle and cancer risk 3 Prev Med Public Health 2010 436 439 471 W 3 0 2 0 2 0 2 0 Overweight Physical Contamination Unsafe and Inactivity Sex 2019 Gynon Inc Smoking appears to have a much more significant effect than physical inactivity Diet could play a greater role than exercise in cancer prevention People are exposed to more cancer causing urban air pollution There are other factors with the same contribution percentage as physical inactivity to study The contribution percentage of physical inactivity is not significant enough to warrant study

Which of the following are reasons for selective reporting Select all that apply A researcher wants the fame for finding the relationship even though the relationship does not exist There can be more money in it It is less work Sometimes people do not want the best evidence to be reported It can represent the truth better

You were comparing rats age and the time they took to run through a maze You measured many other variables and your conclusion is that rats with longer tails took longer Which kind of selective reporting are you doing O not reporting data about all subjects in the sample Obad sampling O not reporting all the variables measured O comparing things that are not comparable