Quant Final
The degree of correlation among independent variables in a regression model is called _____. a. multicollinearity b. interaction c. the sum of squared errors (SSE) d. the coefficient of determination
a. multicollinearity
A null and alternative hypothesis for a one proportion z test are given as H0: p ≥ 0.8, Ha: p < 0.8. This hypothesis test is _____ a. upper-tailed b. two-tailed c. lower-tailed d. incorrectly stated.
c. lower-tailed
The CEO of a company wants to estimate the percent of employees that use company computers to go on Facebook during work hours with 95% confidence. He selects a random sample of 150 of the employees and finds that 53 of them logged onto Facebook that day. Compute the 95% confidence interval for the population proportion. a. b. c. d. (answer choices are math equations)
.35±1.96
Statistical significance at the 0.01 level is _____ than significance at the 0.05 level. a. less informative b. easier to achieve c. more difficult to achieve d. less costly
c. more difficult to achieve
The weekly demand for an item in a retail store follows a uniform distribution over the range 70 to 83. What would be the weekly demand if its corresponding computer-generated value is 0.5? a. 76.5 b. 50.85 c. 90.1 d. 83
a. 76.5
The prespecified value of the independent variable at which its relationship with the dependent variable changes in a piecewise linear regression model is referred to as the _____. a. knot b. watchpoint c. milestone d. tipping point
a. knot
Regression analysis involving one dependent variable and more than one independent variable is known as _____. a. linear regression b. simple regression c. multiple regression d. None of these choices are correct.
c. multiple regression
Two approaches to drawing a conclusion in a hypothesis test are _____. a. one-tailed and two-tailed b. Type I and Type II c. p-value and critical value d. null and alternative
c. p-value and critical value
A description of the range and relative likelihood of possible values of an uncertain variable is known as a _____. a. base-case scenario b. risk analysis c. probability distribution d. simulation optimization
c. probability distribution
A simulation model extends spreadsheet modeling by _____. a. using historical data to make predictions about future values and expected trends b. using real-time values for parameters from the application to formulate solutions c. replacing the use of single values for parameters with a range of possible values d. extending the range of parameters for which solutions are computed
c. replacing the use of single values for parameters with a range of possible values
The difference between the observed value of the dependent variable and the value predicted using the estimated regression equation is known as the _____. a. model parameter b. error term c. residual d. constant term
c. residual
A set of values for the random variables is called a(n) _____. a. combination b. event c. trial d. permutation
c. trial
In the graph of the simple linear regression equation, the parameter ß0 represents the _____ of the true regression line. a. x-intercept b. end-point c. y-intercept d. slope
c. y-intercept
When the mean value of the dependent variable is independent of variation in the independent variable, the slope of the regression line is _____. a. positive b. infinite c. zero d. negative
c. zero
In interval estimation, as the sample size becomes larger, the interval estimate _____. a. gets closer to 1.96 b. becomes wider c. remains the same, since the mean is not changing d. becomes narrower
d. becomes narrower
As the number of degrees of freedom for a t distribution increases, the difference between the t distribution and the standard normal distribution _____. a. becomes larger b. stays the same c. fluctuates d. becomes smaller
d. becomes smaller
A statistics teacher started class one day by drawing the names of 10 students out of a hat and asked them to do as many pushups as they could. The 10 randomly selected students averaged 15 pushups per person with a standard deviation of 9 pushups. Suppose the distribution of the population of number of pushups that can be done is approximately normal. If we would like to capture the population mean with 95% confidence the margin of error would be _____. a. b. c. d. (answers are math equations)
2.262(9/sqrt10)
A large manufacturing plant has analyzed the amount of time required to produce an electrical part and determined that the times follow a normal distribution with mean time μ = 45 hours. The production manager has developed a new procedure for producing the part. He believes that the new procedure will decrease the population mean amount of time required to produce the part. After training a group of production line workers, a random sample of 25 parts will be selected and the average amount of time required to produce them will be determined. If the switch is made to the new procedure, the cost to implement the new procedure will be more than offset by the savings in manpower required to produce the parts. Use the hypotheses: H0: μ ≥ 45 hours and Ha: μ < 45 hours. If the sample mean amount of time is = 43.118 hours with the sample standard deviation s = 5.5 hours, give the appropriate conclusion, for α = 0.025. a. Do not reject H0, do not switch to the new procedure. b. Reject H0, switch to the new procedure. c. Do not reject H0, switch to the new procedure. d. Reject H0, do not switch to the new procedure.
a. Do not reject H0, do not switch to the new procedure.
The _____ function in Excel is used to compute the statistics required to create a histogram. a. FREQUENCY b. RAND c. NORM.INV d. STDEV.S
a. FREQUENCY
The average number of hours for a random sample of mail order pharmacists from company A was 50.1 hours last year. It is believed that changes to medical insurance have led to a reduction in the average work week. To test the validity of this belief, the hypotheses are _____. a. H0: u ≥ 50.1, Ha: u < 50.1 b. H0: u > 50.1, Ha: u < 50.1 c. H0: u = 50.1, Ha: u = 50.1 d. H0: u ≤ 50.1, Ha: u > 50.1
a. H0: u ≥ 50.1, Ha: u < 50.1
_____ refers to the degree of correlation among independent variables in a regression model. a. Multicollinearity b. Rank c. Confidence level d. Tolerance
a. Multicollinearity
Which of the following cannot be modeled by a continuous distribution? a. Number of products produced in an hour b. Height of the finished manufactured product c. Weight of a finished manufactured product d. Length of time it takes to manufacture a product
a. Number of products produced in an hour
The Excel function _____ generates integer values between lower and upper bounds. a. RANDBETWEEN b. UPPER c. LOWER d. RAND
a. RANDBETWEEN
Which of the following parameters is required to convert a computer-generated random variable into a uniform random variable? a. Range of the distribution b. Moments of the distribution c. Variance of the distribution d. Mean of the distribution
a. Range of the distribution
Determine whether the alternative hypothesis is left-tailed, right-tailed, or two-tailed: H0: μ = 11, Ha: μ > 11. a. Right-tailed b. Left-tailed c. Two-tailed d. There is not enough information to make a determination.
a. Right-tailed
Which of the following cannot be described by a discrete probability distribution? a. The cost of parts for manufacturing an item, where the parts can take on any value between $80 and $100. b. The number of units produced in a given day, where 20% of the time 99 units are produced and 80% of the time 100 units are produced. c. The labor cost for manufacturing goods, where one-third of the units cost $10 in labor, one-third cost $15 in labor, and one-third cost $50 in labor. d. Sales of two medical devices in which Device A generates $35 per unit sold and will likely constitute 30% of the sales and Device B generates $50 per unit sold and will likely constitute 70% of the sales.
a. The cost of parts for manufacturing an item, where the parts can take on any value between $80 and $100.
The scatter chart below displays the residuals versus the dependent variable, x. Which of the following conclusions can be drawn based upon this scatter chart? a. The residual distribution is not normally distributed. b. The residuals have a constant variance. c. The model captures the relationship between the variables accurately. d. The model underpredicts the value of the dependent variable for intermediate values of the independent variable.
a. The residual distribution is not normally distributed.
The time it takes to manufacture a product is modeled by a continuous distribution. The time to manufacture one unit can take anywhere from 5 to 6 minutes with equal probability. What distribution can be used to model the random variable, production time? a. Uniform distribution b. Normal distribution c. Binomial distribution d. Discrete probability distribution
a. Uniform distribution
_____ is the process of determining that a simulation model provides an accurate representation of a real system. a. Validation b. Consideration c. Regression d. Verification
a. Validation
The random variables corresponding to the interarrival times of customers and the service times of the servers are commonly part of a(n) _____ simulation. a. discrete-event b. Monte Carlo c. what-if d. risk analysis
a. discrete-event
In the simple linear regression model, the _____ accounts for the variability in the dependent variable that cannot be explained by the linear relationship between the variables. a. error term b. constant term c. residual d. model parameter
a. error term
Prediction of the value of the dependent variable outside the experimental region is called _____. a. extrapolation b. averaging c. forecasting d. interpolation
a. extrapolation
The choice of the probability distribution for a random variable can be guided by _____. a. historical data b. likelihood factors c. an objective function d. forecasting
a. historical data
The process of making a conjecture about the value of a population parameter, collecting sample data that can be used to assess this conjecture, measuring the strength of the evidence against the conjecture that is provided by the sample, and using these results to draw a conclusion about the conjecture is known as _____. a. hypothesis testing b. postulation c. statistical inference d. empirical research
a. hypothesis testing
A simple random sample of size n from a finite population of size N is a sample selected such that each possible sample of size _____. a. n has the same probability of being selected b. N and n have the same probability of being selected c. n has a probability of 0.05 of being selected d. n has a probability of 0.5 of being selected
a. n has the same probability of being selected
A simple random sample of 31 observations was taken from a large population. The sample mean equals 5. Five is a _____. a. point estimate b. population mean c. standard error d. population parameter
a. point estimate
A random sample selected from an infinite population is a sample selected such that each element selected comes from the same _____ and each element is selected _____. a. population; independently b. population; simultaneously c. sample; simultaneously d. sample; independently
a. population; independently
The process of evaluating a decision in the face of uncertainty by quantifying the likelihood and magnitude of an undesirable outcome is known as _____. a. risk analysis b. decision tree analysis c. regression analysis d. data mining
a. risk analysis
A regression analysis involving one independent variable and one dependent variable is referred to as a _____. a. simple linear regression b. data mining c. factor analysis d. time series analysis
a. simple linear regression
The basis for using a normal probability distribution to approximate the sampling distribution of the sample means and population mean is _____. a. the central limit theorem b. the empirical rule c. Chebyshev's theorem d. Bayes' theorem
a. the central limit theorem
A procedure for using sample data to find the estimated regression equation is _____. a. the least squares method b. interval estimation c. extrapolation d. point estimation
a. the least squares method
A disadvantage of the simple what-if analyses is that _____. a. there is no indication of the likelihood of various output values b. there are errors induced as a result of rounding c. the optimal solutions are not guaranteed d. it cannot compute alternate optimal solutions
a. there is no indication of the likelihood of various output values
All the values of computer-generated random numbers are _____. a. uniformly distributed b. Poisson distributed c. lognormally distributed d. normally distributed
a. uniformly distributed
The processes that generate big data can be described by the following four attributes or dimensions: a. volume, variety, veracity, and velocity b. variety, vectors, veracity, and velocity c. tall data, wide data, narrow data, and big data d. volume, variability, veracity, and velocity
a. volume, variety, veracity, and velocity
A _____ analysis involves considering alternative values for the random variables and computing the resulting value for the output. a. what-if b. risk c. cluster d. random
a. what-if
A parameter is a numerical measure from a population, such as _____. a. μ b. p̄ c. s d. x̄
a. μ
The coefficient of determination _____. a. is equal to zero for a perfect fit b. takes values between -1 to +1 c. is used to evaluate the goodness of fit d. is equal to negative one for the poorest fit
c. is used to evaluate the goodness of fit
The CEO of a company wants to estimate the percent of employees that use company computers to go on Facebook during work hours with 95% confidence. He selects a random sample of 150 of the employees and finds that 53 of them logged onto Facebook that day. What is the estimate of the standard error of the proportion σp̄? a. 0.050 b. 0.039 c. 0.350 d. 0.455
b. 0.039
A large manufacturing plant has analyzed the amount of time required to produce an electrical part and determined that the times follow a normal distribution with mean time μ = 45 hours. The production manager has developed a new procedure for producing the part. He believes that the new procedure will decrease the population mean amount of time required to produce the part. After training a group of production line workers, a random sample of 25 parts will be selected and the average amount of time required to produce the parts will be determined. If the switch is made to the new procedure, the cost to implement the new procedure will be more than offset by the savings in manpower required to produce the parts. Use the hypotheses: Ho: μ ≥ 45 hours and Ha: μ < 45 hours. Determine the p value of the test statistic if the sample mean amount of time is = 43.118 hours with the sample standard deviation s = 5.5 hours. a. 0.95818 b. 0.04999 c. 0.04973 d. 0.04354
b. 0.04999
The CEO of a company wants to estimate the percent of employees that use company computers to go on Facebook during work hours with 95% confidence. He selects a random sample of 150 of the employees and finds that 53 of them logged onto Facebook that day. What is the point estimate of the proportion of the population that logged onto Facebook that day? a. 0.53 b. 0.35 c. 0.65 d. 0.25
b. 0.35
What would be the coefficient of determination if the total sum of squares (SST) is 23.29 and the sum of squares due to regression (SSR) is 10.03? a. 0.89 b. 0.43 c. 2.32 d. 0.19
b. 0.43
The profit realized by the sales of a particular item follows a normal distribution with a mean of $0.5 million per quarter and a standard deviation of $0.1 million per quarter. What percent of the quarters can be expected to see a profit of at least $0.5 million? a. 40% b. 50% c. 10% d. 60%
b. 50%
_____ is used to test the hypothesis that the values of the regression parameters ß1, ß2, ... ßq are all zero. a. Extrapolation b. An F test c. The least squares method d. A t test
b. An F test
The population parameters that describe the y-intercept and slope of the line relating y and x, respectively, are _____. a. y and x b. B0 and B1 c. a and B d. a and b
b. B0 and B1
Which of the following is a disadvantage of using simulation? a. Experimenting directly with a simulation model is often not feasible. b. Each simulation run provides only a sample of how the real system will operate. c. Simulation models warn against poor decision strategies by projecting disastrous outcomes such as system failures, large financial losses, and so on. d. The simulation models are used to describe systems without requiring the assumptions that are required by mathematical models.
b. Each simulation run provides only a sample of how the real system will operate.
Which statement is NOT true? a. The probability of making a Type I error is symbolized by α. b. Failing to reject the null hypothesis when it is false is a Type I error. c. Rejecting the null hypothesis when it is true is a Type I error. d. Type II error can occur for both one and two-tailed tests.
b. Failing to reject the null hypothesis when it is false is a Type I error.
A student wants to determine if pennies are really fair when flipped, meaning equally likely to land heads up or tails up. He flips a random sample of 50 pennies and finds that 28 of them land heads up. If p denotes the true probability of a penny landing heads up when flipped, what are the appropriate null and alternative hypotheses? a. H0: p ≤ 0.5, Ha: p ≠ 0.5. b. H0: p = 0.5, Ha: p ≠ 0.5. c. H0: p ≥ 0.5, Ha: p < 0.5. d. H0: p ≥ 28, Ha: p < 28.
b. H0: p = 0.5, Ha: p ≠ 0.5.
The owners of a fast food restaurant have automatic drink dispensers to help fill orders more quickly. When the 12 ounce button is pressed, they would like for exactly 12 ounces of beverage to be dispensed. There is, however, some variation in this amount. The company does not want the machine to systematically over fill or under fill the cups. Which of the following gives the correct set of hypotheses? a. H0: u ≥ 12, Ha: u < 12 b. H0: u = 12, Ha: u ≠ 12 c. H0: u ≤ 12, Ha: u > 12 d. H0: u > 12, Ha: u < 12
b. H0: u = 12, Ha: u ≠ 12
A pizza shop advertises that they deliver in 30 minutes or less or it is free. People who live in homes that are located on the opposite side of town believe it will take the pizza shop longer than 30 minutes to make and deliver the pizza. Write the null and alternative hypotheses that can be used to conduct a significance test. a. H0: u > 30, Ha: u < 30 b. H0: u ≤ 30, Ha: u > 30 c. H0: u < 30, Ha: u > 30 d. H0: u ≥ 30, Ha: u < 30
b. H0: u ≤ 30, Ha: u > 30
_____ refers to the use of sample data to calculate a range of values that is believed to include the value of the population parameter. a. Point estimation b. Interval estimation c. Statistical inference d. Hypothesis testing
b. Interval estimation
A _____ uses repeated random sampling to represent uncertainty in a model representing a real system and that computes the values of model outputs. a. deterministic model b. Monte Carlo simulation c. discrete event simulation d. what-if analysis
b. Monte Carlo simulation
_____ is a statistical procedure used to develop an equation showing how two variables are related. a. Time series analysis b. Regression analysis c. Data mining d. Factor analysis
b. Regression analysis
In reviewing the graph below, which of the following inferences can be drawn about the monthly salary? a. The monthly salary is always less than $3,000. b. The average monthly salary is $3,000. c. The monthly salary is always greater than $3,000. d. The range of the monthly salary distribution is $3,000 to $5,000.
b. The average monthly salary is $3,000.
The scatter chart below displays the residuals versus the dependent variable, x. Which of the following conclusions can be drawn based upon this scatter chart? a. The residuals have a constant variance. b. The model fails to capture the relationship between the variables accurately. c. The residuals are normally distributed. d. The model overpredicts the value of the dependent variable for small values and large values of the independent variable.
b. The model fails to capture the relationship between the variables accurately.
Which of the following inferences about a variable of interest can be drawn from the graph given below? a. The variable can only take the value 30. b. The variable is equally likely to take any value between 20 and 40. c. The variable is more likely to take any value outside the range of 20 and 40. d. The variable is more likely to take the value 20 than 40.
b. The variable is equally likely to take any value between 20 and 40.
_____ is the data set used to build the candidate models. a. Codomain b. Training set c. Validation set d. Range
b. Training set
Larger values of α have the disadvantage of increasing the probability of making a _____. a. normal probability error b. Type I error c. Type II error d. random sampling error
b. Type I error
_____ refers to the data set used to compare model forecasts and ultimately pick a model for predicting values of the dependent variable. a. Codomain b. Validation set c. Range d. Training set
b. Validation set
A variable used to model the effect of categorical independent variables in a regression model which generally takes only the value zero or one is called _____. a. the coefficient of determination b. a dummy variable c. a residual d. interaction
b. a dummy variable
A normally distributed error term with a mean of zero would _____. a. yield biased regression estimates b. allow more accurate modeling c. be a hyperbolic curve d. have values that are symmetric about the variance
b. allow more accurate modeling
Using an α = 0.04, a confidence interval for a population proportion is determined to be 0.65 to 0.75. If the level of significance is decreased, the interval for the population proportion _____. a. does not change b. becomes wider c. becomes narrower d. remains the same
b. becomes wider
The _____ is a measure of the goodness of fit of the estimated regression equation. It can be interpreted as the proportion of the variability in the dependent variable y that is explained by the estimated regression equation. a. interaction variable b. coefficient of determination c. residual d. dummy variable
b. coefficient of determination
A variable used to model the effect of categorical independent variables in a regression model is known as a _____. a. response b. dummy variable c. dependent variable d. predictor variable
b. dummy variable
In Excel, the expression LN(RAND())*(-m) would generate a(n) _____ random variable with mean m. a. lognormal b. exponential c. normal d. logarithmic
b. exponential
The finite correction factor should be used in the computation of the standard deviation of the sample mean and the standard population when n / N is _____. a. less than 0.5 b. greater than 0.05 c. greater than 0.5
b. greater than 0.05
An estimate of a population parameter that provides an interval of values believed to contain the value of the parameter is known as the _____. a. population estimate b. interval estimate c. confidence level d. parameter level
b. interval estimate
The population parameter value and the point estimate differ because a sample is not a census of the entire population, but it is being used to develop the _____. a. standard error b. point estimate c. population parameter d. population mean
b. point estimate
In a simple linear regression analysis the quantity that gives the amount by which the dependent variable changes for a unit change in the independent variable is called the _____. a. standard error b. slope of the regression line c. coefficient of determination d. correlation coefficient
b. slope of the regression line
In a simple linear regression model, y = ß0 + ß1x + ε the parameter ß1 represents the _____. a. error term b. slope of the true regression line c. intercept d. mean value of x
b. slope of the true regression line
The least squares regression line minimizes the sum of the _____. a. absolute deviations between actual and predicted x values b. squared differences between actual and predicted y values c. differences between actual and predicted y values d. absolute deviations between actual and predicted y values
b. squared differences between actual and predicted y values
The process of determining that a computer program implements a simulation model as it is intended is known as _____. a. correlation b. verification c. optimization d. validation
b. verification
In a linear regression model, the variable (or variables) used for predicting or explaining values of the response variable are known as the _____. It(they) is(are) denoted by x. a. residual variable b. regression variable c. independent variable d. dependent variable
c. independent variable
In a random sample of 400 registered voters, 120 indicated they plan to vote for Trump for President. Determine a 95% confidence interval for the proportion of all the registered voters who will vote for Trump. a. (0.29, 0.30) b. (0.27, 0.32) c. (0.25, 0.34) d. Cannot be determined from the information given.
c. (0.25, 0.34)
What would be the value of the sum of squares due to regression (SSR) if the total sum of squares (SST) is 25.32 and the sum of squares due to error (SSE) is 6.89? a. 15.32 b. 31.89 c. 18.43 d. 19.32
c. 18.43
In order to determine an interval for the mean of a population with unknown standard deviation, a sample of 24 items is selected. The mean of the sample is determined to be 23. The number of degrees of freedom for reading the t value is _____. a. 22 b. 21 c. 23 d. 24
c. 23
The t value for a 99% confidence interval estimation based upon a sample of size 10 is _____. a. 1.812 b. 2.576 c. 3.249 d. 1.645
c. 3.249
A statistics teacher started class one day by drawing the names of 10 students out of a hat and asked them to do as many pushups as they could. The 10 randomly selected students averaged 15 pushups per person with a standard deviation of 9 pushups. Suppose the distribution of the population of number of pushups that can be done is approximately normal. The 95% confidence interval for the true mean number of pushups that can be done is _____. a. 5.75 to 24.25 b. 13.02 to 16.98 c. 8.56 to 21.40 d. 11.31 to 18.55
c. 8.56 to 21.40
Which of the following is true of verification? a. It requires an agreement among analysts and managers. b. It deals with the accurate modeling of real system operations. c. It is largely a debugging task. d. It is performed prior to the development of the computer procedure for simulation.
c. It is largely a debugging task.
For a given mean and standard deviation, the _____ function in Excel is used to generate a value for the random variable characterized by a normal distribution. a. VLOOKUP b. FREQUENCY c. NORM.INV d. RAND
c. NORM.INV
What are the two decisions that you can make from performing a hypothesis test? a. Make a Type I error; Make a Type II error b. Reject the alternative hypothesis; Accept the null hypothesis c. Reject the null hypothesis; Fail to reject the null hypothesis d. Accept the null hypothesis; Accept the alternative hypothesis
c. Reject the null hypothesis; Fail to reject the null hypothesis
The scatter chart below displays the residuals versus the dependent variable, x. Which of the following conclusions can be drawn from the scatter chart given below? a. The residual distribution is consistently scattered about zero. b. The regression model follows the standard normal probability distribution. c. The residuals have an increasing variance as the dependent variable increases. d. The model captures the relationship between the variables accurately.
c. The residuals have an increasing variance as the dependent variable increases.
A sample of 37 AA batteries had a mean lifetime of 584 hours. A 95% confidence interval for the population mean was 579.2 < μ < 588.8. Which statement is the correct interpretation of the results? a. The probability that the population mean is between 579.2 hours and 588.8 hours is 0.95. b. 95% of the light bulbs in the sample had lifetimes between 579.2 hours and 588.8 hours. c. We are 95% confident that the mean lifetime of all the bulbs in the population is between 579.2 hours and 588.8 hours. d. None of these statements correctly interpret the results.
c. We are 95% confident that the mean lifetime of all the bulbs in the population is between 579.2 hours and 588.8 hours.
The range of computer-generated random numbers is _____. a. [-8, 0) b. [1, 8] c. [0, 1) d. [-8, 8]
c. [0, 1)
For a population with an unknown distribution, the form of the sampling distribution of the sample mean is _____. a. exactly normal for small sample sizes b. approximately normal for small sample sizes c. approximately normal for large sample sizes d. exactly normal for large sample sizes
c. approximately normal for large sample sizes
If the expected value of the sample statistic is equal to the population parameter being estimated, the sample statistic is said to _____. a. be a random estimator of the population parameter b. have low variability c. be an unbiased estimator of the population parameter d. have high precision
c. be an unbiased estimator of the population parameter
The _____ is an indication of how frequently interval estimates based on samples of the same size taken from the same population using identical sampling techniques will contain the true value of the parameter we are estimating. a. accuracy level b. residual c. confidence level d. tolerance factor
c. confidence level
An input to a simulation model that is selected by the decision maker is known as a ______. a. nonnegativity constraint b. probable input c. controllable input d. random variable
c. controllable input
Assessing the regression model on data other than the sample data that was used to generate the model is known as _____. a. postulation b. approximation c. cross-validation d. graphical validation
c. cross-validation
In a linear regression model, the variable that is being predicted or explained is known as _____. It is denoted by y and is often referred to as the response variable. a. independent variable b. regression variable c. dependent variable d. residual variable
c. dependent variable
A one-tailed test is a hypothesis test in which the rejection region is _____. a. only in the lower tail of the sampling distribution b. in both tails of the sampling distribution c. in one tail of the sampling distribution d. only in the upper tail of the sampling distribution
c. in one tail of the sampling distribution
A statistics teacher started class one day by drawing the names of 10 students out of a hat and asked them to do as many pushups as they could. The 10 randomly selected students averaged 15 pushups per person with a standard deviation of 9 pushups. Suppose the distribution of the population of number of pushups that can be done is approximately normal. What is the standard error of the mean? a. 4.743 b. 3.061 c. 0.900 d. 2.876
d. 2.876
Which of the following functions computes a value such that 2.5% of the area under the standard normal distribution lies in the upper tail defined by this value? a. =NORM.S.INV(0.025) b. =NORM.S.INV(0.05) c. =NORM.S.INV(0.95) d. =NORM.S.INV(0.975)
d. =NORM.S.INV(0.975)
Which of the following Excel functions would generate random integers from 0 to 100? a. =100*RAND( ) b. =SUMIF(A1:A100, 100) c. =RAND( ) d. =RANDBETWEEN(0, 100)
d. =RANDBETWEEN(0, 100)
Which of the following numbers cannot result from the Excel function =NORM.INV(RAND( ), 100, 10)? a. 121 b. 115 c. 99 d. All of these numbers can result from this Excel function.
d. All of these numbers can result from this Excel function.
_____ refers to the scenario in which the relationship between the dependent variable and one independent variable is different at different values of a second independent variable. a. Autocorrelation b. Covariance c. Multicollinearity d. Interaction
d. Interaction
Which of the following regression models is used to model a nonlinear relationship between the independent and dependent variables by including the independent variable and the square of the independent variable in the model? a. Multiple regression model b. Simple regression model c. Least squares regression model d. Quadratic regression model
d. Quadratic regression model
The _____ function is used to generate a pseudorandom number in Excel. a. NORM.INV() b. ROUND() c. FREQUENCY() d. RAND()
d. RAND()
Which statement is NOT true? a. The greater the level of confidence, the larger the z-score. b. The greater the level of confidence, the wider the confidence interval. c. The greater the level of confidence, the more likely it is that the confidence interval actually includes the true population mean. d. Rejecting the null hypothesis when it is true is a Type II error.
d. Rejecting the null hypothesis when it is true is a Type II error.
The proportion of dental procedures that are extractions is 0.16. Which of the following exemplifies a Type I error in this situation? a. We reject the claim that the proportion of dental procedures that are extractions is 0.16 when the proportion is actually different from 0.16. b. We fail to reject the claim that the proportion of dental procedures that are extractions is 0.16 when the proportion is actually 0.16. c. We fail to reject the claim that the proportion of dental procedures that are extractions is 0.16 when the proportion is actually different from 0.16. d. We reject the claim that the proportion of dental procedures that are extractions is 0.16 when the proportion is actually 0.16.
d. We reject the claim that the proportion of dental procedures that are extractions is 0.16 when the proportion is actually 0.16.
A Type I error is committed when _____. a. a true alternative hypothesis is not accepted b. the critical value is greater than the value of the test statistic c. the validity of a claim was rejected d. a true null hypothesis is rejected
d. a true null hypothesis is rejected
In a _____ distribution, a random variable can take any value in a specified range. a. discrete probability b. cumulative c. relative frequency d. continuous probability
d. continuous probability
The _____ is the range of values of the independent variables in the data used to estimate the regression model. a. codomain b. confidence interval c. validation set d. experimental region
d. experimental region
Prediction of the mean value of the dependent variable y for values of the independent variables x1, x2, . . . , xq that are outside the experimental range is called _____. a. dummy variable b. interaction c. overfitting d. extrapolation
d. extrapolation
The values for random variables in a Monte Carlo simulation are ______. a. taken from forecasting analysis b. selected manually c. derived secondarily using formulas d. generated randomly from probability distributions
d. generated randomly from probability distributions
You are _____ to commit a Type I error using the 0.05 level of significance than using the 0.01 level of significance. a. less likely b. twice as likely c. equally likely d. more likely
d. more likely
A distribution of a random variable for which values extremely larger or smaller than the mean are increasingly unlikely can possibly be modeled as a(n) _____ probability distribution. a. binomial b. gamma c. exponential d. normal
d. normal
The type of distribution shown in the graph below is a(n) _____ distribution. a. exponential b. beta c. uniform d. normal
d. normal
Fitting a model too closely to sample data, resulting in a model that does not accurately reflect the population is termed as _____. a. hypothesizing b. approximation c. postulating d. overfitting
d. overfitting
The purpose of statistical inference is to make estimates or draw conclusions about a _____. a. mean of the sample based upon the mean of the population b. statistic based upon information obtained from the population c. sample based upon information obtained from the population d. population based upon information obtained from the sample
d. population based upon information obtained from the sample
The outcome of a simulation experiment is a(n) _____. a. objective function b. single number c. what-if scenario d. probability distribution for one or more output measures
d. probability distribution for one or more output measures
In simulation analysis, the _____ of random variables can be adjusted to determine the impact of the assumptions about the shape of the uncertainty on the results. a. relative frequencies b. ranges c. manual generations d. probability distributions
d. probability distributions
A(n) _____ is an input to a simulation model whose value is uncertain and described by a probability distribution. a. identifier b. constraint c. decision variable d. random variable
d. random variable
The scatter chart below displays the residuals versus the dependent variable, t. Which of the following conclusions can be drawn based upon this scatter chart? a. model captures the relationship between the variables accurately. b. model is time-invariant. c. residuals are normally distributed. d. residuals are not independent.
d. residuals are not independent.
The value of the _____ is used to estimate the value of the population parameter. a. sample parameter b. population estimate c. population statistic d. sample statistic
d. sample statistic
One reason a sample may fail to represent the population of interest is _____. a. population proportion b. measurement error c. statistical inference d. sampling error
d. sampling error
A _____ is used to visualize sample data graphically and to draw preliminary conclusions about the possible relationship between the variables. a. Gantt chart b. contingency table c. pie chart d. scatter chart
d. scatter chart
In the graph of the simple linear regression equation, the parameter ß1 is the _____ of the true regression line. a. x-intercept b. y-intercept c. end-point d. slope
d. slope
The process of making estimates and drawing conclusions about one or more characteristics of a population through analysis of sample data drawn from the population is known as _____. a. Bayesian inference b. deductive inference c. inductive inference d. statistical inference
d. statistical inference
The graph of the simple linear regression equation is a(n) _____. a. parabola b. hyperbola c. ellipse d. straight line
d. straight line
The _____ is a measure of the error that results from using the estimated regression equation to predict the values of the dependent variable in the sample. a. error term b. residual c. sum of squares due to regression (SSR) d. sum of squares due to error (SSE)
d. sum of squares due to error (SSE)
In a base-case scenario, the output is determined by assuming _____. a. best values that can be expected for the random variables of a model b. the mean trial values for the random variables of a model c. worst values that can be expected for the random variables of a model d. the most likely values for the random variables of a model
d. the most likely values for the random variables of a model
When the expected value of the point estimator is equal to the population parameter it estimates, it is said to be _____. a. symmetric b. predicted c. precise d. unbiased
d. unbiased
The random numbers generated using Excel's RAND function follows a _____ probability distribution between 0 and 1. a. random b. normal c. binomial d. uniform
d. uniform
A pizza shop advertises that they deliver in 30 minutes or less or it is free. People who live in homes that are located on the opposite side of town believe it will take the pizza shop longer than 30 minutes to make and deliver the pizza. A random sample of 50 deliveries to homes across town was taken and the mean time was computed to be 32 minutes. What is the appropriate symbol to represent the value, 32? a. p = 32 b. μ = 32 c. n = 32 d. x = 32
d. x = 32