Final
False
Determine if the statement is true or false. In conducting a hypothesis test, what is usually to be proven statistically is identified as the null hypothesis. Question content area bottom Part 1 True False
True
Determine whether the following statement is true or false. Skewness describes the lack of symmetry of data. Question content area bottom Part 1 True Your answer is correct. False
20.90
The details of the clock sales at a supermarket for the past 6 weeks are shown in the table below. The time series appears to be relatively stable, without trend, seasonal, or cyclical effects. The simple moving average value of k is set at 2. Calculate the value of the simple moving average mean absolute percentage error. Round to two decimal places. Week Units sold 1 88 2 44 3 54 4 65 5 72 6 85 Question content area bottom Part 1 A. 20.90 Your answer is correct. B. 23.45 C. 25.56 D. 14.39
standard normal distribution
Which of the following types of distributions use z-values to establish confidence intervals? Question content area bottom Part 1 Gaussian q-distribution log-normal distribution t-distribution standard normal distribution
C. Small sample sizes generate a low value of the power of the test.
Which statement is true about the value of the power of the test? Question content area bottom Part 1 A. A low value will enable valid conclusions to be made. B. Small sample sizes incur higher costs than large sample sizes. C. Small sample sizes generate a low value of the power of the test. Your answer is correct. D. A low value will help in detecting small differences in sample statistics.
B. 254.8371
An extract from the database of a construction company is shown. The table shows the height of walls in feet and the cost of raising them. The estimated simple linear regression equation is given as Y=b0+b1X. What is the value of the coefficient b0? Round to four decimal places. (Hint: Use Excel functions). Height (ft) Cost ($) 4 670 3 430 7 810 9 1100 6 790 8 880 5 760 11 1200 Question content area bottom Part 1 A. 86.8170 B. 254.8371 Your answer is correct. C. 0.0107 D. −2.2532
D. 86.8170
An extract from the database of a construction company is shown. The table shows the height of walls in feet and the cost of raising them. The estimated simple linear regression equation is given as Y=b0+b1X. What is the value of the coefficient b1? Round to four decimal places. (Hint: Use Excel functions). Height (ft) Cost ($) 4 670 3 430 7 810 9 1100 6 790 8 880 5 760 11 1200 Question content area bottom Part 1 A. 254.8371 B. −2.1463 C. 0.0107 D. 86.8170
True
Determine whether the following statement is true or false. The expected value and variance of the Poisson distribution are equal to λ. Question content area bottom Part 1 True Your answer is correct. False
False
Determine whether the following statement is true or false. Two variables can only have a statistical relationship if there is a cause-and-effect factor between them. Question content area bottom Part 1 True False
A. It uses a panel of experts, whose identities are typically kept confidential from one another, to respond to a sequence of questionnaires.
How does the Delphi method used for forecasting work? Question content area bottom Part 1 A. It uses a panel of experts, whose identities are typically kept confidential from one another, to respond to a sequence of questionnaires. Your answer is correct. B. It uses measures that are believed to influence the behavior of a variable that the researcher wishes to forecast. C. It obtains forecasts through a comparative analysis with a previous situation. D. It uses a single measure that weights multiple indicators and provides a measure of overall expectation.
single moving average model
If the given time series has no trend and no seasonality, which model is the most appropriate forecasting model to determine the forecast of the time series? Question content area bottom Part 1 Holt-Winters no-trend smoothing model Holt-Winters additive model single moving average model Your answer is correct. double exponential smoothing model
A. Type II error
Robin Inc. feared that the average company loss is running beyond $34,000. It initially conducted a hypothesis test on a sample extracted from its database. The hypothesis was formulated as H0: average company loss $34,000 vs. H1: average company loss>$34,000. The test resulted in favor of Robin Inc.'s loss not exceeding $34,000. Detailed study of company accounts later revealed that the average company loss had run up to $37,896. What error was made during the hypothesis test? Question content area bottom Part 1 A. Type II error Your answer is correct. B. Type III error C. Type I error D. Type IV error
C. 24 units
The data for the number of hand-held gaming devices sold for the past 5 weeks are 15 units, 20 units, 25 units, 30 units, and 17 units respectively. The time series appears to be relatively stable, without trend, seasonal, or cyclical effects; thus, a moving average model would be appropriate. Setting k=3, what is the three-period moving average forecast for week 6? Question content area bottom Part 1 A. 30 units B. 20 units C. 24 units Your answer is correct. D. 17 units
80 clocks
The details of the clock sales at a supermarket for the past 6 weeks are shown in the table below. The time series appears to be relatively stable, without trend, seasonal, or cyclical effects. The simple moving average value of k is set at 2. If the smoothing constant is assumed to be 0.7, and setting F1 and F2=A1, what is the exponential smoothing sales forecast for week 7? Round to the nearest whole number. Week Units sold 1 88 2 44 3 54 4 65 5 72 6 85 Question content area bottom Part 1 A. 80 clocks Your answer is correct. B. 50 clocks C. 70 clocks D. 60 clocks
14.25
The details of the clock sales at a supermarket for the past 6 weeks are shown in the table below. The time series appears to be relatively stable, without trend, seasonal, or cyclical effects. The simple moving average value of k is set at 2. What is the simple moving average mean absolute deviation? Round to two decimal places. Week Units sold 1 88 2 44 3 54 4 65 5 72 6 85
14.39
The details of the clock sales at a supermarket for the past 6 weeks are shown in the table below. The time series appears to be relatively stable, without trend, seasonal, or cyclical effects. The simple moving average value of k is set at 2. What is the simple moving average root mean square error? Round to two decimal places. Week Units sold 1 88 2 44 3 54 4 65 5 72 6 85
A. It is one that repeats at fixed intervals of time, typically a year, month, week, or day.
Time-series models may exhibit seasonal effects or cyclical effects. What about a seasonal effect makes it different from a cyclical effect? Question content area bottom Part 1 A. It is one that repeats at fixed intervals of time, typically a year, month, week, or day. Your answer is correct. B. It describes ups and downs over a time frame such as several years. C. It has no trend, is relatively constant, and only exhibits random behavior. D. It is based on analysis of historical time-series data and are predicated on the assumption that the future is an extrapolation of the past.
multicollinearity
What is the condition called when two or more independent variables in the same regression model can predict each other better than the dependent variable? Question content area bottom Part 1 autocorrelation homoscedasticity multicollinearity Your answer is correct. heteroscedasticity
C. It is another name for the sample correlation coefficient, r.
What is true about the Excel output Multiple R? Question content area bottom Part 1 A. It is often referred to as the coefficient of determination. B. A negative slope of the regression line denotes a positive Multiple R. C. It is another name for the sample correlation coefficient, r. Your answer is correct. D. A value of 0 indicates positive correlation.
D. The rejection region occurs in the tails of the sampling distribution of the test statistic.
What statement is true about the rejection region? Question content area bottom Part 1 A. With a true null hypothesis, the test statistic falls into the rejection region. B. The rejection region is chosen to determine the probability of a Type I error. Your answer is not correct. C. If the test statistic is in the nonrejection region, the null hypothesis is rejected. D. The rejection region occurs in the tails of the sampling distribution of the test statistic.
C. H0: population parameter=constant vs. H1: population parameter≠constant
Which hypotheses represent a valid one-sample hypothesis test? Question content area bottom Part 1 A. H0: population parameter>constant vs. H1: population parameter≤constant B. H0: population parameter<constant vs. H1: population parameter≥constant C. H0: population parameter=constant vs. H1: population parameter≠constant Your answer is correct. D. H0: population parameter≠constant vs. H1: population parameter=constant
B. It is the distribution of the means of all possible samples of fixed size n from a population.
Which of the following accurately describes a sampling distribution of the mean? Question content area bottom Part 1 A. It is the mean of any one sample from a group of related populations of different sizes. B. It is the distribution of the means of all possible samples of fixed size n from a population. Your answer is correct. C. It is the mean of half the samples from a related group of populations. D. It is the mean distribution of any one sample from a group of samples of varying sizes from a population.
uniform distribution
Which of the following characterizes a continuous random variable for which all outcomes between some minimum and maximum value are equally likely? Question content area bottom Part 1 normal distribution lognormal distribution exponential distribution uniform distribution
A. It is a sampling method based on selecting every nth item from a population.
Which of the following describes periodic sampling? Question content area bottom Part 1 A. It is a sampling method based on selecting every nth item from a population. Your answer is correct. B. It is a sampling method based on selecting a time and then sampling the products after that time. C. It is a sampling method exclusively used for population that is divided into subsets. D. It is a sampling method based solely on expert opinion.
D. It is the square root of the variance.
Which of the following describes standard deviation? Question content area bottom Part 1 A. It is the average of the greatest and least values in the data set. B. It is the average of the squared deviations of the observations from the mean. C. It is the difference between the first and third quartiles of a data set. D. It is the square root of the variance.
A. the time to complete a specific task
Which of the following is a continuous random variable? Question content area bottom Part 1 A. the time to complete a specific task Your answer is correct. B. the number of hits on a Web site link C. the number of new hires in a year D. the outcomes of rolling two dice
A. A median is not affected by outliers; a mean is affected by outliers.
Which of the following is a difference between a mean and a median? Question content area bottom Part 1 A. A median is not affected by outliers; a mean is affected by outliers. Your answer is correct. B. A mean is an observation that occurs most frequently; a median is the average of all observations. C. A median is not meaningful for ratio data; a mean is meaningful to ratio data. D. A mean divides the data half above it and half below it; a median does not.
variance
Which of the following is a weighted average of the squared deviations from the expected value? Question content area bottom Part 1 kurtosis variance Your answer is correct. skewness mean difference
C. Because samples are only a subset of the population
Which of the following is the inherent reason why sampling errors occur? Question content area bottom Part 1 A. Because samples represent the whole population B. Because the means cannot be accurately estimated using samples C. Because samples are only a subset of the population Your answer is correct. D. Because samples never provide enough data to estimate standard deviation
D. Obtaining sufficient information to draw a valid inference about a population
Which of the following is the purpose of sampling? Question content area bottom Part 1 A. Calculating all variables and observations within a population B. Enumerating all the values in the population C. Measuring all items of interest for a particular interest or investigation D. Obtaining sufficient information to draw a valid inference about a population
C. If the process that generates the outcomes is known, probabilities can be deduced from theoretical arguments.
Which of the following is true about the classical definition of probability? Question content area bottom Part 1 A. The probability that an outcome will occur is simply the relative frequency associated with that outcome. B. It is based on observed data. C. If the process that generates the outcomes is known, probabilities can be deduced from theoretical arguments. Your answer is correct. D. It is based on judgment and experience.
D. If the CS value is between 0.5 and 1, the skewness is considered to be moderate.
Which of the following is true of the coefficient of skewness (CS)? Question content area bottom Part 1 A. If the CS is closer to zero, the degree of skewness is considered to be high. B. If the CS is positive, the distribution of values tails off to the left. C. If the CS value is between −0.5 and −1, the skewness is considered negligible. D. If the CS value is between 0.5 and 1, the skewness is considered to be moderate.
C. They must be randomly scattered.
While checking for linearity by examining the residual plot, what must be true of the residuals? Question content area bottom Part 1 A. They must exhibit a linear trend. B. They must form a parabolic shape. C. They must be randomly scattered. Your answer is correct. D. They must be below the x-axis.