SCM 200 Final Exam True or False
True or False: A mean of a data set is a relative measure.
False
True or False: A multiple liner regression model has multiple dependent variables.
False
True or False: A percentile of a population is an example of a parameter.
False
True or False: A relative frequency distribution can sometimes have relative frequencies less than zero.
False
True or False: A sampling distribution is a distribution of the results of one sample.
False
True or False: According to the Central Limit Theorem, as the size of the sample increases, the distribution of the observations in the sample approximates a normal distribution.
False
True or False: Another name for a scatterplot is a histogram.
False
True or False: Assume a matched pairs test for a mean difference with a two-tailed alternative hypothesis and the number of paired differences is n=4. If the computed value of the test statistic is t=2.353, then the p-value would be equal to .05.
False
True or False: For a given multiple regression model, an adjusted R square value is always greater than the corresponding unadjusted R square value.
False
True or False: Given a two-tailed t-test for one mean with 6 degrees of freedom and the value of the test statistic computed from the sample data t = -1.44 then the p-value would be equal to .10.
False
True or False: If a distribution of a large data set of heights Is symmetric and bell-shaped, then 99.7% of the values fall within one standard deviation of the mean.
False
True or False: If common causes of variation are present in a process, then the process must be unstable.
False
True or False: If the coefficient if determination is equal to .49, it necessarily follows the the correlation coefficient is equal to +.70.
False
True or False: In finding the Z value for a 95% confidence interval, we could either ue the 5th percentile value or the 95th percentile value.
False
True or False: Increasing the sample size, but using the same level of confidence, produces a confidence interval for a population mean mu that has a greater likelihood of containing the true mean being estimated.
False
True or False: Other things being equal, a 92% confidence interval will be wider than a 96% confidence interval.
False
True or False: The brand of a loaf of bread is an ordinal variable.
False
True or False: The multiple liner regression equation y hat = 30 + 1.2x1 + 4x2 - 3x3 has (n-3) degrees of freedom.
False
True or False: The theoretical approach to assigning probabilities uses what has occurred in the past to predict the future.
False
True or False: The units of a regression coefficient are the units of X.
False
True or False: Trials must be dependent in a binomial probability problem.
False
True or False: Two events that have no sample space outcomes in common, and therefore cannot occur simultaneously, are always complementary events.
False
True or False: When an analyst rejects the null hypothesis that the population slope is equal to zero, the conclusion is that the X variable is not a statistically significant predictor.
False
True or False: A data set with CV level of 64 has moderate variability.
True
True or False: A refrigerator manufacturer buys parts from a supplier. The probability of a defective part is 10%. Assuming the trials are identical and independent, if three parts are selected at random, the probability that one of the parts will be defective is .243.
True
True or False: A regression coefficient is an absolute measure.
True
True or False: A sample consisting of the numbers 1, 3, 8 has a sample variance equal to 13.
True
True or False: An example of an interval estimate would be a confidence interval for a population mean.
True
True or False: If a p-value for a given hypothesis testing problem is computed to be .016 and the level of significance is .01, the null hypothesis would be accepted.
True
True or False: If the middle of monthly sales of TV sets is between 50 and 150 sets, it follows that the 10th percentile would be 50 sets and the 90th percentile would be 150 sets.
True
True or False: If the standard deviation of a set of numbers is equal to zero, then it necessarily follows that the range of those numbers must also be equal to zero.
True
True or False: In a paired test a blocking variable, unlike a factor, controls for the variability in a problem that is known.
True
True or False: In an upper-tailed test of the difference of two proportions, the z-value was calculated to be 1.40. The p-value for this test would then be .0808.
True
True or False: In forecasting the trend in sales from time series data with a simple linear regression equation, the independent variable would be time.
True
True or False: In the standard normal z-distribution, the probability (or area) between z = -.45 and z = +1 is the same as the probability between z = -1 and z = +.45.
True
True or False: Ordinal data is a type of qualitative data.
True
True or False: Standard deviation of sales = $100 Standard deviation of advertising = $300 correlation = .97 If we are predicting advertising from sales, the regression coefficient is 2.91.
True
True or False: The box for naming a column in Excel is below the ribbon on the far left of the spreadsheet.
True
True or False: The coefficient of variation computed from the three sample values 30,40,50 would be equal to 25.
True
True or False: The distance of a race is a ratio scale variable.
True
True or False: The expected value of a random variable is the long-run average of the distribution of the random variable.
True
True or False: The sample range is a biased estimator of the population range.
True
True or False: The t-value to use for setting a 90% level of confidence for a population mean with a sample size n = 21 is test t = 1.725
True
True or False: There is more variability in the t-statistic than the z-statistic because both the mean and standard deviation can vary from sample to sample.
True
True or False: When the coefficient of determination is equal to one, the standard error of the estimate will be equal to zero.
True