QNT/275 FINAL EXAM QUESTIONS AND ANSWERS

QNT/275 Final Results of these answers is 26/30 (86.67%) If you can figure out which of the four questions are wrong, then you can get 100% The regression model y = A + Bx + e is: • a nonlinear model • a deterministic model • a probabilistic model • an exact relationship The mean of a discrete random variable is the mean of its: • frequency distribution • percentage distribution • probability distribution • second and third quartiles The p-value is the: • smallest significance level at which the null hypothesis cannot be rejected • largest significance level at which the alternative hypothesis can be rejected • largest significance level at which the null hypothesis can be rejected • smallest significance level at which the null hypothesis can be rejected A quantitative variable is the only type of variable that can: • be graphed • have no intermediate values • assume numeric values for which arithmetic operations make sense • be used to prepare tables To make tests hypotheses about more than two population means, we use the: • analysis of variance distribution • normal distribution • t distribution • chi-square distribution In a survey regarding job satisfaction, 574 in a sample of 934 female job-holders stated that they are satisfied with their jobs, while 500 in a sample of 755 male job-holders stated that they are satisfied with their jobs. The null hypothesis is that the proportions of all female and male job-holders who are satisfied with their jobs are the same. The alternative hypothesis is that the proportion of female job-holders who are satisfied with their jobs is lower than the proportion of male job-holders stated who are satisfied with their jobs. The significance level is 2.5%. What is the critical value of z for the hypothesis test? • -2.05 • -1.96 • -2.33 • -2.17 In a game of four-handed Hearts, all 52 cards of a standard deck are dealt, so that each player starts each round with 13 cards in a hand. Suppose player A’s hand has three clubs, six diamonds, two hears, and two spades. What is the relative frequency of spades, rounded to two decimal places, dealt to player A? • 0.75 • 0.15 • 1.5 • 0.25 Two events are independent if the occurrence of one event: • Means that the second event is certain to occur. • Does not affect the probability of the occurrence of the other event. • Affects the probability of the occurrence of the other event. • Means that the second event cannot occur. The model y = A + Bx is a: • Deterministic model • Nonlinear model • Probabilistic model • Stochastic model For a goodness-of-fit test, the frequencies obtained from the performance of an experiment are the: • Objective frequencies • Observed frequencies • Expected frequencies • Subjective frequencies Which of the following pairs of events are mutually exclusive? • Male and yes • Female and yes • Female and male • Female and no A researcher wants to test if the mean annual salary of all lawyers in a city is different than $110,000. The null hypothesis for this example will be that the population mean is: • Less than to $110,000 • Not equal to $110,000 • Equal to $110,000 • Greater than to $110,000 A qualitative variable is the only type of variable that: • Cannot be measured numerically • Cannot be graphed • Can assume an uncountable set of values • Can assume numerical values For the one-tailed test, the p-value is: • The area under the curve to the same side of the value of the sample statistic as is specified in the alternative hypothesis • Twice the area under the curve to the same side of the value of the sample statistic as is specified in the alternative hypothesis • The area under the curve between the mean and the observed value of the sample statistic • Twice the area under the curve between the mean and the observed value of the sample statistic Which of the following assumptions is not required to use ANOVA? • The samples drawn from different populations are random and independent. • All samples are of the same size. • The populations from which the samples are drawn (approximately) normally distributed. • The populations from which the samples are drawn have the same variance. The alternative hypothesis is a claim about a: • Parameter, where the claim is assumed to be true until it is declared false • Statistic, where the claim is assumed to be false until it is declared true • Statistic, where the claim is assumed to be true if the null hypothesis is declared false • Parameter, where the claim is assumed to be true if the null hypothesis is declared false. In a one-way ANOVA, we analyze only one: • Variable • Sample • Population • Mean In a hypothesis test, a Type I error occurs when: • A true null hypothesis is not rejected • A false null hypothesis is not rejected • A true null hypothesis is rejected • A false null hypothesis is rejected A continuous random variable x has a right-skewed distribution with a mean of 80 and a standard deviation of 12. The sampling distribution of the sample mean for a sample of 50 elements taken from this population is: • Approximately normal • Not normal • Skewed to the right • Skewed to the left Two paired or matched samples would imply that: • Data are collected on two variables from the elements of two independent samples • Two data values are collected from the same source (elements) for two dependent samples • Data are collected on one variable from the elements of two independent samples • Two data values are collected from the same source (elements) for two independent samples The mean of a discrete random variable is its: • Expected value • Upper hinge • Second quartile • Box-and-whisker measure An error that occurs because of chance is called: • Nonsampling error • Probability error • Sampling error • Mean error A researcher wants to test if elementary school children spend less than 30 minutes per day on homework. The alternative hypothesis for this example will be that the population mean is: • Less than or equal to 30 minutes • Equal to 30 minutes • Less than 30 minutes • Not equal to 30 minutes For small degrees of freedom, the chi-square distribution is: • Skewed to the right • Skewed to the left • Symmetric • Rectangular A sample of 16 from a population produced a mean of 86.9 and a standard deviation of 14.3. A sample of 18 from another population produced a mean of 75.4 and a standard deviation of 15.9. Assume that the two populations are normally distributed and the standard deviations of the two populations are equal. The null hypothesis is that the two population means are equal, while the alternative hypothesis is that the mean of the first population is greater that the man of the second population. The significance level is 1%. What is the critical value of t for the hypothesis test? • 2.441 • 2.449 • 2.738 • 2.733 If you divide the number of elements in a sample with a specific characteristic by the total number of elements in the sample, the dividend is the: • Sampling distribution • Sample proportion • Sample distribution • Sample mean You toss a coin nine times and observe 3 heads and 6 tails. This event is a: • Simple event • Multiple outcome • Compound event • Multinomial sample point A linear regression: • Contains only two variables • Gives a relationship between three variables that can be described by a line • Gives a relationship between two variables that cannot be described by a line • Gives a relationship between two variables that can be described by a line We can use the analysis of variance procedure to test hypotheses about: • Two or more population means • The proportion of one population • The mean of one population • Two or more population proportions In a hypothesis test, a Type II error occurs when: • A false null hypothesis is not rejected • A false null hypothesis is rejected • A true null hypothesis is not rejected • A true null hypothesis is rejected