MAS291 ^^, MAS KEY - Summer2021

B

(Choose 1 answer) A CD has 12 tracks on it and these are to be played in ra·ndom order. Suppose that you have time to listen to only 5 tracks before you go out. What is the probability that the 5 played will be the first 5 in order on the box? A. 5/12 B. 1/95040 C. 1/3991680 D. 1/792 E. None of the other choices is correct

A

(Choose 1 answer) A Web site randomly selects one product among 5 products to discount each day. The color printer of interest to you is discounted today. What is the expected number of days until this product is again discounted? A. 5 B. 20 C. None of the other choices is correct D. 15 E. 10

D

(Choose 1 answer) A batch of 50 machined parts contains 5 that do not conform to customer requirements. Determine the range of the random variable that is the number of parts that do not conform to customer requirements in a sample of 8 parts selected without replacement from the batch. A. {0, 1, ... , 8} B. None of the other choices is correct C. {0, 1, 2, ... , 50} D. { 0, 1, 2, 3, 4, 5}

C

(Choose 1 answer) A group of students were asked if they carry a credit card. The responses are listed in the table. If a student is selected at random. find the probability that he or she owns a credit card given that the student is a freshman. Round your answer to three decimal places. TABLE Class |Credit Card Carr..|Not a Credi Card... |Total Freshman | 24 | 36 | 60 Sophomore | 37 | 3 | 40 Total | 61 | 39 | 100 A. None of the other choices is correct B. 0.240 C. 0.400 D. 0.393 E. 0.600

A

(Choose 1 answer) A paper bag contains two red balls and one blue ball. A plastic bag contains three blue balls and one red ball. A coin is tossed. If it .{g!_ls heads ue_, the paper bag Is selected and a ball is drawn. If the coin falls tajls up, the plastic bag is selected and a ball is drawn. If a red ball is selected, what is the probability that it came from the paper bag? A. 0.727 B. None of the other choices is correct C. 0.543 D. 0.819 E. 0.338

B

(Choose 1 answer) A polltaker asked graduating college seniors how many times they had given blood in the last year. The results of the survey are given in the table. The random variable X represents the number of times a person gave blood and P(x) represents the probability of selecting a graduating college who had given blood that percent of the time. What is the standard deviation for the number of times a person gave blood based on this poll? table X 0 1 2 3 P(X) 0.30 0.25 0.20 0.25 A. 1.34 B. 1.16 C. 2.23

B

(Choose 1 answer) A private opinion poll is conducted for a politician to determine what proportion of the population favors decriminalizing marijuana possession. How large a sample is needed in order to be 99% confident that the sample proportion will not differ from the true proportion by more than 6%? Let Zo.oo5 = 2.575 A. None of the other choices is correct B. 461 C. 921 D. 11

E

(Choose 1 answer) A quality-control engineer inspects a random sample of 3 batteries from each lot of 24 car -batterjes that is ready to be shipped. If such a lot contains 6 batteries with slight defects, what is the probability that the inspector's sample will contain only one of the batteries with defects? A. 0.1832 B. 0.5464 C. 0.8168 D. None of the other choices is correct E. 0.45361

E

(Choose 1 answer) A random sample of 40 students has a mean annual earnings of 3120. Assume the population standard deviation is 677. Construct the confidence interval for the population mean. Use a 95% confidence level. Let Zo.o5 = 1.645, Z0.025 = 1.96, t0.05,39 = 2.023, t0.025,39 = 2.331 A. (1987, 2346) B. None of the other choices is correct C. (210, 110) D. (4812, 5342) E. (2910, 3330)

C

(Choose 1 answer) A salesperson knows that 20% of her presentations result in sales. Use the normal approximation formula for the Binomial distribution to find the probabilities that in the next 60 presentations at least 9 result in sales. Let P(Z < -1.13) = 0.1268 and P(Z < -0.81) = 0.2089. A. 0.7911 B. None of the other choices is correct C. 0.1241 D. 0.8732

E

(Choose 1 answer) A survey of senior citizens at a doctor's office shows that 52% take blood pressure-loweri,ng medication, 43% take cholesterol-lowering medication, and 5% take both medications. What is the probability that a senior citizen takes either blood pressure-lowering or cholesterol-lowering medication? A. None of the other choices is correct B. 0.14 C. 0.85 D. 1 E. 0.90

E

(Choose 1 answer) A survey of senior citizens at a doctor's office shows that 52% take blood pressure-lowering medication. 43% take cholesterol-lowering medication. and 5% take both medications. What is the probability that a senior citizen takes either blood pressure-lowering or cholesterol-lowering medication? A. 0.85 B. 1 C. 0.14 D. None of the other choices is correct E. 0.90

E

(Choose 1 answer) An engineering professional body estimates that 70°/2 of the students taking undergraduate engineering courses are in favour of studying of statistics as part of their studies. If this estimate is correct, use the normal formula for Binomia,I distributions to approximate the probability that more than 700 undergraduate engineers out of a random sample of 1000 will be in favour of studying statistics. Let P(Z < 0.035 ) = 0.514; P(Z < 0) = 0.5. A. 0.486 B. 0.5 C. None of the other choices is correct D. 0.643 E. 0.514

D

(Choose 1 answer) At a computer manufacturing company, the actual size of computer chips is normally distributed with a mean of 1 centimeter and a standard deviation of 0.1 centimeter. A random sample of 12 computer chips is taken. What is the probability that the samp'le mean will be below 0.95 centimeters? Let P(Z < -1. 73) = 0.04, P(Z < -0.34) = 0.36 and P(Z < 0) = 0.5. A. 0.36 B. 0.64 C. 0.96 D. 0.04 E. None of the other choices is correct

C

(Choose 1 answer) Choose the correct phrase to fill in the blank: The _____for a particular class is equal to the class frequency divided by the tota·I number of observations. A. stem-and-leaf display B. bar graph C. class relative frequency D. None of the other choices is correct E. class percentage

D

(Choose 1 answer) Construct a 90% confidence interval for the population mean. Assume the population has a normal distribution. A sample of 15 randomly selected students has a g_rade point average of 2.86 with a standard deviation of 0. 78. Let = t dưới 0.15,14 = 1.76, Z dưới 0.05 = 1.654 A. (2.41, 3.42) B. None of the other choices is correct C. (2.28, 3.66) D. (2.51, 3.21) E. (2.37, 3.56)

E

(Choose 1 answer) Entertainment Software Association would like to test if the standard deviation for the age of gamers is equal to 5.0 years. The standard deviation for the age from a random sample of 20 gamers is 5.6 years. Using the significance level of 0.10, find the lower critical value for this hypothesis test. A. 11.651 B. None of the other choices is true C. 12.443 D. 13.240 E. 10.117

D

(Choose 1 answer) Flip a coin three times. create the sample space of possible outcomes. (Below. H stands for Head, T stands for Tail) A. {HHH, TTT. THT. HTH, HHT. TTH. HTH} B. None of the other choices is correct C. {HTT. THT, HTH. HHH, ITH, TTT} D. {HHH. HHT. HTH, HIT, THH, THT, ITH, ITT} E. {HHH, HTT, HTH, TTT, HTT. THH, HHT. THT}

D

(Choose 1 answer) For each of the following pairs of events, which are subsets of the set of all possib e outcomes when a coin is tossed three times, choose the (s) is (are) independent. A. E1: the first toss comes up tail; E2: the second coin comes up head. B. E1: the first toss comes up tail; E2: first, second and third toss, come up head in a row C. E1: the second toss comes up tail; E2: second, and not third toss, come up head in a row D. All of the others

B

(Choose 1 answer) It is desired to estimate the average total compensation of CEOs in the Service industry. Data were randomly collected from 35 CEOs and the 94% confidence interval was calculated to be (3451260, 7536180). Which of the following interpretations is correct? A. 94% of the sampled total compensation values fell between 3451260 and 7536180 B. We are 94% confident that the average total compensation of all CEOs in the Service industry falls in the interval 3451260 to 7536180 C. We are 94% confident that the mean of the sampled CEOs falls in the interval 3451260 to 7536180 D. In the population of Service industry CEOs, 94% of them will have total compensations that fall in the interval 3451260 to 7536180

A

(Choose 1 answer) Jared was working on a project to look at global warming and accessed an Internet site where he captured average global surface temperatures from 1866. Which of the four methods of data collection was he using? A. Retrospective study B. Observation C. Surveying D. Experimentation

C

(Choose 1 answer) Let X be a uniform random variable over the interval (0. 8) . What is the probability that the random variable X has a value greater than 3? A. 0.575 B. None of the other choices is correct C. 0.625 D. 0.750 E. 0.500

A

(Choose 1 answer) Let X be a uniform random variable over the interval [1, 9] . What is the probability that the random variable X has a value less than 6? A. 0.625 B. 0.875 C. 0.400 D. 0.500 E. None of the other choices is correct

C

(Choose 1 answer) Let X represent the amount of time it takes a student to park in the library parking lot at the university. If we know that the distribution of parking times can be modeled using an exponential distribution with a mean of 4 minutes, find the probability that it will take a randomly selected student more than 10 ,minutes to park in 1he library lot. A. 0.329680 B. None of the other choices is correct C. 0.082085 D. 0.917915 E. 0.670320

C

(Choose 1 answer) Parking at a large university has become a very big problem. University administrators are interested in determining the average parking time (e.g. the time it takes a student to find a parking spot) of its students. An administrator inconspicuously followed 130 students and carefully recorded their parking times. Identify the sample of interest to the university administration. A. location of the parking spot B. parking time of a student C. parking times of the 130 students D. type of car (import or domestic)

A

(Choose 1 answer) Suppose a sample of n = 15 items is drawn from a population of manufactured products and the weight, X, of each item is recorded. Prior experience has shown that the weight has a probability distribution with mean = 6 ounces and standard deviation = 2.5 ounces. Which of the following is true about the sampling distribution of the sample mean if a sample of size 15 is selected? A. All of the others are correct. B. The shape of the sample distribution is approximately normal. C. The mean of the sampling distribution is 6 ounces. D. The standard deviation of the sa.mpling distribution is 2.5 ounces.

E

(Choose 1 answer) Suppose data is obtained from 20 pairs of (x,y) and the sample correlation coefficient is 0. 7. Find the test statistic if you want 95% confident that there exist a significant positive linear correlation between x and y. A. 0.05 B. 4.27 C. None of the other choice is correct D. 4.38 E. 4.16

D

(Choose 1 answer) Suppose the ra ndom variable X has a geometric distribution with p = 0.3. Determine P(X > 1). A. 04 B. 0.6 C. 0.3 D. 0.7 E. None of the other choices is correct (công thức để làm: P(X<=k) 1-q^k)

B

(Choose 1 answer) The correlation between two variables is given by r = 1.0. What does this mean? A. The best straight line through the data is horizontal. B. There is a perfect positive relationship between the two variables C. None of the other choices is correct. D. There is a perfect negative relationship between the two variables. E. All of the points must fall exactly on a horizontal straight line.

D

(Choose 1 answer) The data below are the final exam scores of 3 randomly selected statistics students and the number of hours they studied for the exam. Calculate the correlation coefficient r. Hours. x: 8 10 6 Scores. y: 72 87 66 A. 0.991 B. 0.654 C. None of the other choices is correct D. 0.971 E. 0.761

A

(Choose 1 answer) The mean replacement time for a random sample of 12 microwave ovens is 8.6 years with a standard deviation of 2.7 years. Construct the 98% confidence interval for the population variance. Assume the data are normally distributed. (Let X trên 2 dưới 0.01,11 = 24.72 dưới X 2 & 0.99,11 = 3.05 A. (3.2, 26.3) B. None of the other choices is correct C. (1.2, 9. 7) D. (1.8, 5.1) E. (3.1, 22.5)

B - Poisson distribution

(Choose 1 answer) The number of calls received by a car towing service averages 21.6 per day (per 24-hour period). After finding the mean number of calls per hour, find the probability that in a randomly selected hour the number of calls is 4. A. 0.01000 B. 0.01111 C. 0.01223 D. None of the other choices is correct E. 0.01389

A

(Choose 1 answer) The random variable X represents the number of boys in a family of three children. Assuming that boys and girls are equally likely, find the mean and standard deviation for the random variable X. A. mean: 1.50; standard deviation: 0.87 B. mean: 2.25; standard deviation: 0.76 C. mean: 1.50; standard deviation: 0.76 D. None of the other choices is correct E. mean: 2.25; standard deviation: 0.87

A

(Choose 1 answer) Two white mice mate. The male has both a white and a black fur-color gene. The female has only white fur-color genes. The fur color of the offspring depends on the pairs of fur-color genes that they receive. Assume that neither the white nor the black gene dominates. List the possible outcomes. W = white and B = black. Create the sample space of possible outcomes. A. WW, BW B. None of the other choices is correct C. WB, BW D. WW, BB E. WW, WW

D

(Choose 1 answer) You are dealt two cards successively without replacement from a standard deck of 52 playing cards. Find the proba'bility that the first card is a two and the second card is a ten. Round your answer to three decimal places. A. 0.250 B. None of the other choices is correct C. 0.994 D. 0.006 E. 0.500

C

A CD has 12 tracks on ii and these are to be played in random order. Suppose that you have time to listen to only 5 tracks before you go out. What is the probability that the 5 played are your 5 favourite tracks n any order)? A. 5/12 B. 1/95040 C. 1/792 D. 1/3991680 E. None of the other choices is correct

E

A Company has just brought out an annual report in which the capital investment and profits were given for the past few years. hình ảnh Capital investment, x | 10 | 12 | 18 | 25 Profits, y | 15 | 14 | 23 | 38 Assume that an unbiased estimator for variance of the error is 8.34. Find an estimated standard error for slope of regression line. A. 0.03 B. 0.02 C. None of them D. 0.17 E. 0.12 F. 2.89

D

A common rule of thumb for determining how many classes to use when developing a frequency distribution with classes is: A. no fewer than 6 classes. B. None of the other choices is correct. C. equals to 0.25 times the number of date values. D. between 5 and 20 classes.

C. experiments

A method of gathering data when subjects are exposed to certain treatments and the data of interest is recorded is known as A. None of the other choices is correct B. observation C. experiments D. retrospective

C

A soft drink company has a filling machine that can be set at different levels to produce different average fill amounts. The conpany sets the machine to provide a mean fill of 12 ounces. The standard deviation on the machine is hypothesis test is to be 0.20 ounces. Assuming that the hypothesis test is to be performed using a random sample of n = 100 cans, which of the following would be the coffect fonnulation of the null and alternative? (i) Ho :u /= 12 ounces H1 : u = 12 ounces (il) Ho : u = 12 ounces H1 : u /= 12ounces (iii) Ho : X <= 12 ounces H1 : x > 12 ounces A. (iii) B. None of the other choices is correct C. (ii) D. (i)

B

A.n airline clairns tha.t only 6% of all lost luggage is never found. If, in a random sample, 17 of 200 pieces of lost luggage are not found, test the null hypothesis p = 0.06 against the alternative hypothesis p > 0.06 at a= 0.05. Let Zo.o5 = 1.65 (i) zo = 1.489, fail ·to reject H0 (ii) zo = 1.489, reject H0 (iii) zo = 1.836, fail to reject H0 (iv) zo = 1.836, reject H0 A. (iv) B. (i) C. (iii) D. None of the other choices is correct E. (ii)

D

A_______________ is a portion of a population that is representative of the population from which it is selected. A. population B. survey C. None of the other choices is true D. sample E. parameter

A

An ento111ologist vvrites an ruticle in a scientific joun1al vvhich clai1ns that fevver than 12 in tenthousand 111ale firetlies are unable to produce hght cine to a genetic 111utation. Express the null hypo thesis Ho and the alternative hypothesis H1 in syn1bolic fonu. Use the paran1eter p, the tn1e propo1tion of fireflies unable to produce light. (i) Ho: p < 0.0012, H1 : p 0.0012 (ii) Ho: p = 0.0012, H1: p > 0.0012 (iii) Ho: p > 0.0012, H1: p 0.0012 (iv) Ho: p = 0.0012, H1 : p < 0.0012 A. (iv) B. (iii) C. (ii) D. (i)

B

Casualty data from the great flu epidemic of 1918 were collected for a study. This represents what type of study? A. None of them. B. Retrospective study. C. An experiment. D. Observational study.

B

Choose correct statements Select one: A. The significance level of the test is also called its β-error B. The P-value is the smallest level of significance at which the null hypothesis would be rejected. C. Critical values are contained inside the critical region of the test.

A

Choose one true statement Select one: A. random sample is selected in such a way so that every possible sample has the same probability of being selected. B. random variable is a value that is less than 1.

A

Choose the correct phase to fill in the blank: The___for a particular class is equal to the class frequency divide by the total number of observations. A. class percentage B. stem-and-leaf display C. class relative frequency D. None of the other choice is correct E. bar graph

C

Consider the following sample data: 25 11 6 4 2 17 9 6 For these data the median is____________ A. None of the other choices is correct B. 3.5 C. 7.5 D. 10

E. parameter

Data that describe a characteristic aboata that describe a characteristut a population is known as a_______. A. statistic B. None of the other choices is true C. survey D. sample E. parameter

A

Find the probability of answering the two multiple choice questions correctly if random guesses are made. Assume the questions each have five choices for the answer. Only one of the choices is corect A. 0.04 B. 0.02 C. 0.4 D. None of the other choices is correct E. 0.004

D

Flip a coin three times, create the sample space of possible outcomes. (Below, H stands for Head, T stands for Tail). A. {HHH, TTT, THT, HTH, HHT, TTH, HTH} B. None of the other choices is correct. C. {HTT, THT, HTH, HHH, TTH, TTT} D. {HHH, HHT, HTH, HTT, THH, THT, TTH, TTT} E. {HHH, HTT, HTH, TTT, HTT, THH, HHT, THT}

D

For each of the following pairs of events, which are subsets of the set of all possible outcomes when a coin us tossed three times, choose the pair(s) is(are) independent. A. E1: the first toss comes up tail; E2: the second coin comes up head B. E1: the first toss comes up tail; E2: first, second and third toss, come up head in a row C. E1: the second toss comes up tail; E2: second, and not third toss, come up head in a row D. All of the others

C

In a simple linear regression model the slope coefficient measures___________________ A. change in X which the model predicts for a unit change in Y B. the value of Y for any given value of X C. change in Y which the model predicts for a unit change in X D. None of the other choices is correct. E. the ratio Y/X

C

In a simple linear regression model the slope coefficient measures _____ _ A. the change in X which the model predicts for a unit change in Y B. the value of Y for any given value of X C. the change in Y which the model predicts for a unit change in X D. None of the other choices is correct E. the ratio Y/X

D

In its standardized form, the normal distributionSelect one: A. cannot be used to approximate discrete probability distributions. B. has a mean of 1 and a variance of 0. C. has an area equal to 0.5. D. be used to approximate discrete probability distributions

B

Jared was working on a project to look at global warming and accessed an Internet site where he captured average global surface temperatures from 1866. Which of the four methods of data collection was he using? A. Surveying B. Retrospective study C. Experimentations D. Observation

A

Let X be a random variable with density function | x^2 f(x) = | 3 if -1 < x < 2 | 0 elsewhere Find the expected value of Y = 4X + 3. A. 8 B. 10 C. None of the other choices is correct D. 9 E. 7

D

Let X be the discrete random varaible with unifo rm distribution X | 1 | 15 P | 0.5 | 0.5 Let F(x) be the cumulative distribution function of X. Evaluate F(5). A. 0.2 B. 0.3 C. 0.4 D. 0.5 E. None of the other choices is correct

B

Let X be the number of freshmen in the course MAS291. Identify whether Xis discrete or continuous. A. Continuous B. Discrete C. None of the other choices is correct

C. Discrete

Let X be the number of freshmen in the required course, MAS291. Identify whether X is discrete or continuous. A. None of the other choices is correct B. Continuous C. Discrete

A

Past experience indicates that the time for high school seniors to complete a standardized test is a normal random variable with a mean of 35 minutes. If a random sample of 20 high school so niors took an average of 33.1 minutes to complete this test with a standard deviation of 4.3 minutes, test the hypothesis at the 0.025 level of significance that u = 35 minutes against the alternative that u < 35 minutes. Let t0.02,19 = 2.09. A.... 1.98. fail to reject Ho B.... 1.98. reject Ho C.... 0.099. fail to reject Ho D.... 0.099. reject Ho

A

Retrospective Study, observational study and designed experiment are three basis methods of______ Select one: A. collecting data B. analyzing data C. using data to make decisions, solve problems. D. showing data E. None of these

B

Retrospective, Observational, Designed experiment are three basic methods ofSelect one: A. presentation data. B. collecting data. C. analyzing data.

B

Some fields in statistics: Select one: A. quantifying the risks involed in decisions made every day. B. the collection, presentation, analysis and use of data to make decisions, solve problems.

E

Suppose that P(AIB) = 0.6, P(A) = 0.5 and P(B) = 0.1. Find the value of P(BIA). A. 0.20 B. 0.30 C. None of the other choices is correct D. 0.06 E. 0.12

A

Suppose the 1nean ,veight of King Penguins found in an Antarctic colony last yeru· vvas 1 "i 4 kg. In a sainple of 35 penguins sruue tin1e this year in the sruue colony, the 1uean penguin ,veight is 14.6 kg. As:;'luue tl1e sainple stru1dard deviation is 2.5 kg. i\t a significai1ce level of 0.05, cai1 vve reject the null hypothesis that the 111eru1 penguin weight does not differ fi·on1 last year? Let To.02.5;34 = 2.032 (i) t0 = -1.8931, reject H0 (ii) t0 = -1.8931. fail to reject H0 (iii) t0 = 1.8931, reject H0 (iv) t0 = 1.8931, fail to reject H0 A. (ii) B. (i) C. (iii) D. (iv)

B

Suppose the cumulative distribution function of the random variable X is 0 x < 0 F(x) = { 0.2x 0 <= X < 4 0.4x + 0.64 4 <= x < 9 1 9 <= x DetermineP(X < 3). A. 0 B. 0.6 C. 0.76 D. None of the other choices is correct E. 1

E

Suppose you want to test the claim that µ:t 31.5, with known cr. Ifthe sample size is n = 81 and the level of significance a= 0 .1, when should you reject H0: Let Z.o.oo5 = 2.575, Z.o.01 = 2 .33, Z.0.025 = 1.96 and .Z.o.os = 1.645. A. None of the other choices is correct B. Reject HO if the test statistic is greater than 2.575 or less than -2.575. C. Reject HO if the test statistic is greater than 2.33 or less than -2.33 D. Reject HO 1if the test statistic is greater than 1.96 or less than -1.96 E. Reject H0 if the test statistic is greater than 1.645 or less than -1.645

B

Test for significance of regression is the test of....Select one: A. None of others B. H₀: β₁ = 0 versus H₁ : β₁ ≠ 0 C. H₀ : β₀ = 0 versus H₁ : β₁ ≠ 0

D

The collection and summarization of the socioeconomic and physical characteristics of the employees of a particular firm is an example of_______________ A. a statistic B. inferential statistics C. a parameter D. descriptive statistics

B

The correlation between two variables is given by r = 1.0. What does this mean? A. The best straight line through the data is horizontal. B. There is a perfect possitive relationship between the two variables C. None of the other choices is correct. D. There is a perfect negative relationship between the two variables. E. All of the points must fall exactly on a horizontal straight line.

A

The correlation coefficient between variables X and Y is possitive and close to 1. The relationship between the variables X and Y is__________________ A. a strong linear relationship and as X increases, Y increases. B. a weak linear relationship and as X increases, Y increases. C. None of the other choices is correct. D. a weak linear relationship and as X increases, Y decreases. E. a strong linear relationship and as X increases, Y decreases.

A

The discrete random variable X has the probability mass function f(x) = x^3 / 16 + 1/32; x = 0,1,2,3 Determine P(X > 1). A. 0.875 B. 0.6875 C. None of the other choices is correct D. 0.3125 E. 0.96875

C

The following data represents the high ambient temperature for a pruticular city over the past 16 days. 52 56 56 58 59 60 62 65 69 73 73 74 76 76 77 78 Construct a stem and leaf display for this data. 5 2 6 6 8 9 6 0 2 5 9 (i) 73346678 A. None of the other choices is true B. (ii) C. (i) D. (iii)

B

The following is Excel output of a simple regression model. Summary output ..... ..... ..... ..... Coefficients| Standord Eror| tStat Intercept | 11.2 | 3.226763084 | 3.470970663 X Variable 1 | -0.475 | 0.346229693 | -1.371921618 What is the value of the test statistic for testing whether the regression intercept coefficient is equal to 10? A. 4.02 B. 0.37 C. 3.47 D. 2.15 E. None of the other choices is true

B

The following statements, which are true? Select one: A. When the number of observations is large, dot diagram is usually difficult to identify any specific patterns in the variability. B. Dot diagram is a very useful plot for displaying a small body of data. C. Dot diagram is not a convenient way to see any unusual data features.

A

The interquartile range (IQR) is (i) Q3 + Q2 (ii) Q3 - Q2 (iii2 Qs +Qi (iv) Qs - Qi {v) Q2 - Qi A. (iv) B. None of the other choices is correct C. (iii) D. (v) E. (ii) Fi (i)

C

The manager at the ABT restaurant wanted to investigate the effect of music on the average revenue per customer. Each night for one month, fast-paced music was played. The following month, sloe-spaced music was played every night. The average revenue per customer for each month was compared. Ths method of gathering data is known as A. None of the other choices is correct. B. experiments. C. observation. D. retrospective.

C

The manager at the ABT restaurant wanted to investigate the effect of music on the average revenue per customer. Each night for one month. fast-paced music was played. The following month. slow·paced music was played every night. The average revenue per customer for each month was compared. This method of gathering data is known as A. None of the other choices is correct B. experiments. C. observation. D. retrospective

A

The most frequently occurring data value is Select one: A. sample model B. quartile C. sample median D. percentile

A

The process of using sample statistics to draw conclusions about true population parameters is called _______________ A. statistical inference. B. descriptive statistics C. sampling. D. the scientific method

A

The random variable X has the cumulative distribution function 0 x < 1/8 F(x) = {0.2 1/8 <= x < 1/4 0.9 1/4 <= x < 3/8 1 3/8 <= x Find the ptubability mass function at x = 1. A. 1 B. 0.9 C. None of the other choices is correct D. 0 E. 0.2

B

The residuals represent A. None of the other choices is correct B. the difference between the actual Y values and the predicted Y values. C. the difference between the actual Y values and the mean of Y. D. the square root of the slope. E. the predicted value of Y for the average X value.

B

The residuals represent___________________ A. the predicted value of Y for the average X value. B. the difference between the actual Y values and the predicted Y values. C. None of the other choices is correct. D. the difference between the actual Y values and the mean of Y. E. the square root of the slope.

D

The tin1e for a worker to assemble a component is normally distributed ,vith mean 15 minutes a,nd variance 4. Denote the n1ean assembly times of 16 day-shift ,vorkers and 9 night-shift ,vorkers by X and Y, respectively. Assume that the asse1nbly times of the workers are mutually independent. Con1pute P(X - Y < -1.5) Let P(Z <-1.9) = 0.0294, P(Z <-1.8) = 0.0359, P(Z <-1.6) = 0.0559 and P(Z <-1.5) = 0.0668. A. 0.0294 B. 0.0668 C. 0.0559 D. 0.0359 E. None of the other choices is correct

D

The_________________for a particular class is equal to the class frequency divided by the total number of observations. A. class percentage B. stem-and-leaf display C. bar graph D. class relative frequency E. None of the other choices is correct.

C

Those methods involving the collection, presentation, and characterization of a set of data in order to properly describe the various features of that set of data are called ...Select one: A. the scientific method. B. statistical inference. C. descriptive statistics. D. sampling.

C

Tossing a coin 3 times. Let A denote the event exactly 2 heads are thrown. List the sample points in A. (H = Head, T = Tail) A. {HHT, HHT, HTH, THH} B. {HHT, TTH, THH} C. {HHT, HTH, THH} D. {HHT, HTH, THH, HHH} E. None of the other choices is correct.

E

Two white mice mate. The male has both a white and a black fur-color gene. The female has only white fur-color genes. The fur color of the offspring depends on the pairs of fur-color genes that they receive. Assume that neither the white nor the black gene dominates. List the possible outcomes. W = white and B = black. Create the sample space of possible outcomes. A. WW, WW B. WB, BW C. None of the other choices is correct D. WW, BB E. WW, BW

D

When an ordered set of data is divided into four equal parts, the division point is called: Select one: A. mean B. percentiles C. median D. quartile

A

When products and processes are designed and developed with designed experiments, thet enjoy____________ A. All of the others B. better performance C. higher reliability D. lower overall costs

D

Which following statement(s) is (are) true? Select one: A. Observational Study is a basic method of presentation data B. Observational Study is a basic method of analysis data C. None of these D. Observational Study is a basic method of collecting data

D

Which following statement(s) is (are) true?Select one: a. Mechanistic model is not directly developed from our theoretical understanding of the underlying mechanism. b. Mechanistic model is not built from our underlying knowledge of the basic physical mechanism. c. Emprical model directly developed from our theoretical understanding of the underlying mechanism. d. Probability models help quantify the risk involved in statistical inference.

B

Which of the following cannot be a probability?Select one: A. 86% B. 4/3 C. 1 D. 0.4

D

Which of the following is a discrete quantitative variable? A. The distance you drove yesterday. B. The Dow Jones Industrial average C. The volume of water released from a dam D. The number of employees of an insurance company

D

Which of the following is discrete uantitative variable? A. The distance you drove yesterday. B. The Dow Jones Industrial average. C. The volume of water released from a dam. D. The number of employees of an insurance company.

D

Which of the following is not an element of descriptive statistical problems? A. Tables, graphs, or numerical summary tools. B. The population or sample of interest. C. Identification of patterms in the data. D. An inference made about the population based on the sample.

A

Which of the following is the most frequently used measure of variation? A. The standard deviation B. None of the other choices is correct C. The range D. The mode

A

Which statement is true for the scores of 1, 2, 3, 4, 5, 5, 7, 8, 9, and 10? A. The mean is greater than the median. B. The mode is greater than the median. C. The median is greater than the mean. D. The mean is less than the mode.