Thẻ ghi nhớ: MAS291 Theory | Quizlet

Data that describe a characteristic about a population is known as a ________.

A. parameter

B. sample

C. statistic

D. survey

E. None of the other choices is true

A

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____________

A. statistical inference.

B. descriptive statistics.

C. sampling.

D. the scientific method.

B

The federal government requires manufacturers to monitor the amount of radiation emitted through the closed door of a microwave oven. One manufacturer measured the radiation emitted by 42 microwave ovens and recorded the values. What is the population?

A. The set of microwave ovens produced by the manufacturer.

B. The subset of 42 microwave ovens whose emission were measured.

C. The set of microwave ovens produced by all manufacturers.

A

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 210 students and carefully recorded their parking times. Identify the population of interest to the university administration.

A .The entire set of faculty, staff, and students that park at the university.

B. The parking times of the 210 students from whom the data were collected.

C. The parking times of the entire set of students that park at the university.

D. The students that park at the university between 9 and 10 AM on Wednesdays.

C

A ________ is a portion of a population that is representative of the population from which it is selected.

A. sample

B. parameter

C. population

D. survey

E. None of the other choices is true

A

An employee at the local ice cream parlor asks three customers if they like chocolate ice cream. What is the population?

A. three selected customers

B. all women customers.

C. all men customers

D. all customers

D

Retrospective study___________

A. uses current data.

B. uses future data.

C. uses historical data.

D. None of them

C

A Bank of America employee records the amount of time that customers spend using the ATM machine at her branch. This method of gathering data is known as_____________

A. observation.

B. experiments.

C. retrospective

D. None of the other choices is correct

A

A stock analyst compares the relationship between stock prices and earnings per share to help him select a stock for investment. What type of the description is?

A. Observation study

B. Experiment

C. Retrospective study

A

A method of gathering data while the subjects of interest are in their natural environment, often unaware they are being watched, is known as____________

A. observation.

B. experiments.

C. retrospective

D. None of the other choices is correct

A

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. experiments.

B. observation.

C. retrospective

D. None of the other choices is correct

A

(Choose 1 answer)

A method of gathering data when subjects are exposed to certain treatments and the data of interest is recorded is known as_________________

A. experiments.

B. observation.

C. retrospective

D. None of the other choices is correct

A

An event is ____________

A. a collection of elementary events.

B. the list of possible outcomes that can occur from a selection or decision.

C. similar to an experiment but not controlled by the decision maker.

D. more frequently found in business than in other disciplines.

A

Let X be the number of freshmen in the course MAS291. Identify whether X is discrete or continuous.

A. Discrete

B. Continuous

C. None of the other choices is correct

A

Which of the following is a discrete quantitative variable?

A. The number of employees of an insurance company.

B. The volume of water released from a dam.

C. The distance you drove yesterday.

D. The Dow Jones Industrial average.

A

How many baseball teams of nine members can be chosen from among twelve boys, without regard to the position played by each member?

A. 780

B. 1150

C. 2001

D. 220

E. None of the other choices is correct

D

Which of the following is a discrete random variable?

A. The number of eggs that hens lay in a month

B. The price of a product

C. The average height of Vietnamese adults

D. The yield of wheat in a country

A

The average number of hours spent completing statistics homework for a randomly selected group of statistics students is an example of what type of variable?

A. continuous-quantitative variable

B. qualitative variable

C. discrete-quantitative variable

D. None of the other choices is true

A

Which of the following is a continuous quantitative variable?

A. The number of gallons of milk sold at the local grocery store yesterday.

B .The color of a student's eyes.

C. The amount of milk produced by a cow in one 24-hour period.

D. The number of employees of an insurance company.

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____________

A. statistical inference.

B. descriptive statistics.

C. sampling.

D. the scientific method.

B

A stock analyst compares the relationship between stock prices and earnings per share to help him select a stock for investment. What type of the description is?

A. Observation study

B. Experiment

C. Retrospective study

A

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. Experimentation

C. Observation

D. Retrospective study

D

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, BB

B. WB, BW

C. WW, BW

D. WW, WW

E None of the other choices is correct

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, HTH, THH, HHH}

B. {HHT, HTH, THH}

C. {HHT, TTH, THH}

D. {HHT, HHT, HTH, THH}

E. None of the other choices is correct

B

The outcome of an experiment is the number of resulting heads when a nickel and a dime are flipped simultaneously. What is the sample space for this experiment?

A. {0, 1, 2}

B. {HH, HT, TH, TT}

C. {nickel, dime}

D. {HH, HT, TT}

E. None of the other choices is correct

A

Flip a coin twice, create the sample space of possible outcomes. (Below, H stands for Head, T stands for Tail)

A. {HH, TT, HT, HT}

B. {HT, TH}

C. {HH, HT, TH, TT}

D. {HH, HT, TT}

E. None of the other choices is correct

C

The ________________ for a particular class is equal to the class frequency divided by the total number of observations.

A. class relative frequency

B. bar graph

C. stem-and-leaf display

D. class percentage

E. None of the other choices is correct

A

A large retail company gives an employment screening test to all prospective employees. Frankin Gilman recently took the test and it was reported back to him that his score placed him at the 80th percentile. Therefore:

A. 80 people who took the test scored below Franklin.

B. None of the other choices is correct

C. Frankin was in the bottom 20 percent of those that have taken the test.

D. Frankin scored as high or higher than 80 percent of the people who took the test.

D

The human body temperature is normally distributed with the mean of 99 (degree F) and a standard deviation of 0.5 (degree F). A random sample of 99 is selected, describe the sampling distribution for the sample mean.

A. Normal with a mean of 99 and a standard deviation of 0.05

B. Normal with a mean of 1 and a standard deviation of 0.05

C. Normal with a mean of 1 and a standard deviation of 0.005

D. Normal with a mean of 99 and a standard deviation of 0.005

E. None of the other choices is correct

A

Which of the following is true regarding the sampling distribution of the mean for a large sample size?

A. It has a normal distribution with the same mean and standard deviation as the population.

B. It has the same shape, mean, and standard deviation as the population.

C. It has a normal distribution with the same mean as the population but with a smaller standard deviation.

D. It has the same shape and mean as the population, but has a smaller standard deviation.

C

Assume that human body temperatures are normally distributed with a mean of 98 (degree F) and a standard deviation of 0.5(degree F). Describe the sampling distribution for the sample mean body temperature of 50 selected persons.

A. Normal with a mean of 98(degree F) and a standard deviation of 0.07(degree F)

B. Normal with a mean of 98(degree F) and a standard deviation of 0.01(degree F)

C. Approximately normal with a mean of 98(degree F) and a standard deviation of 0.07(degree F)

D. Approximately normal with a mean of 98(degree F) and a standard deviation of 0.01(degree F)

E. None of the other choices is correct

A

Currently, quarters have weights that are normally distributed with a mean of 6.35g and standard deviation 0.5g. If 280 different quarters are inserted into the vending machine, describe the sampling distribution for the sample mean weight.

A. Normal with a mean of 6.35g and a standard deviation of 0.03g

B. Normal with a mean of 6.35g and a standard deviation of 0.002g

C. Approximately normal with a mean of 6.35g and a standard deviation of 0.03g

D. Approximately normal with a mean of 6.35g and a standard deviation of 0.002g

E None of the other choices is correct

A

A ________ represents all possible subjects of interest.

A. population

B. statistic

C. parameter

D. sample

E. None of the other choices is true

A

Retrospective study___________

A. uses current data.

B. uses future data.

C. uses historical data.

D. None of them

C

A method of gathering data when subjects are exposed to certain treatments and the data of interest is recorded is known as_________________

A. experiments.

B. observation.

C. retrospective

D. None of the other choices is correct

A

The amount of television viewed by today's youth is of primary concern to Parents Against Watching Television (PAWT). 250 parents of elementary school-aged children were asked to estimate the number of hours per week that their child watches television. Identify the type of data collected by PAWT.

A. qualitative

B. quantitative and continuous

C. quantitative and discrete

B

The expected value of a negative binomial random variable with parameter p and r (0

D

A 99% confidence interval estimate can be interpreted to mean that______________

(i) we have 99% confidence that we have selected a sample whose interval does include the population mean.

(ii) if all possible samples are taken and confidence interval estimates are developed, 99% of them would include the true population mean somewhere within their interval

A. (i)

B. (i) && (ii)

C. Both (i) and (ii)

D. Nether (i) nor (ii)

C

Suppose a 95% confidence interval for µ turns out to be (1000, 2100). Give a definition of what it means to be 95% confident in an inference.

A. 95% of the observations in the entire population fall in the given interval.

B. In repeated sampling, 95% of the intervals constructed would contain the population mean.

C. 95% of the observations in the sample fall in the given interval.

D. In repeated sampling, the population parameter would fall in the given interval 95% of the time.

B

It is desired to estimate the average total compensation of CEOs in the Service industry. Data were randomly collected from 18 CEOs and the 97% confidence interval was calculated to be (2,181,260; 5,836,180). Based on the interval above, do you believe the average total compensation of CEOs in the Service industry is more than 3,000,000?

A. I am 97% confident that the average compensation is 3,000,000.

B. Yes, and I am 97% confident of it.

C. Yes, and I am 78% confident of it.

D. I cannot conclude that the average exceeds 3,000,000 at the 97% confidence level.

D

A statistics instructor believes that fewer than 20% of Evergreen Valley College (EVC) students attended the opening night midnight showing of the latest Harry Potter movie. She surveys 84 of her students and finds that 11 of attended the midnight showing. The Type I error is believing that the percent of EVC students who attended is____________

A. at least 20%, when in fact, it is less than 20%

B. at least 20%, when in fact, it is 20%

C. less than 20%, when in fact, it is at least 20%

D. less than 20%, when in fact, it is less than 20%

C

An entrepreneur is considering the purchase of a coin-operated laundry. The current owner claims that over the past 5 years, the average daily revenue was $675 with a standard deviation of $75. A sample of 46 days reveals a daily average revenue of $625. If you were to test the null hypothesis that the daily average revenue was $675, which test would you use?

A. Z-test (using normal distribution) of a population proportion

B. t-test (using Student distribution) of population mean

C. Z-test (using normal distribution) of a population mean

D. t-test (using Student distribution) of a population proportion

C

Which of the following is FALSE about the slope of regression line?

A. The slope of estimated regression line is an unbiased estimator for the slope of population regression line

B. The slope of estimated regression line has Student's t-distribution with degree of freedom n-2

C. The slope of estimated regression line has Student's t-distribution with degree of freedom n-1

C

Which of the following statement is FALSE about the Least Square method?

A. We try to minimize the sum of squares of the errors between two sets of points.

B. We try to minimize the sum of absolute difference of the errors between two sets of points.

C. Least Squares method is an estimation technique used for estimating the parameters of linear regression models.

D. We always find the slope and y-intercept of regression line by using Least Square method.

E. None of them

B

The correlation when we use y to predict x is _______ the correlation when we use x to predict y.

A. the same as

B. greater than

C. less than

D. None of the other choices is correct.

A

Assuming a linear relationship between X and Y, if the coefficient of correlation equals to -0.30, then__________________

A. the slope is negative.

B. the variance of X is negative.

C. variable X is larger than variable Y.

D. there is no correlation.

E. None of the other choices is correct

A

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 ofthe slope.

E. the predicted value onfor the average X value.

B

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. equal to 0.25 times the number of data values

D. between 5 and 20 classes.

D

Suppose a 95% confidence interval for populafion mean turns out to be (1000, 2100). To make more useful inferences from the data, it is desired

to reduce the width ofthe confidence interval. Which of the following will result in a reduced interval width?

A. Both increase the sample size and decrease the confidence level.

B. Decrease the confidence level.

C. Increase the sample size. .

D. Both increase the confidence level and decrease the sample size.

D