QNT 351 Final Exam ANSWERS ARE HERE 1) The main purpose of descriptive statistics is toA. summarize data in a useful and informative mannerB. make inferences about a populationC. determine if the data adequately represents the populationD. gather or collect data2) The general process of gathering, organizing, summarizing, analyzing, and interpreting datais calledA. statisticsB. descriptive statisticsC. inferential statisticsD. levels of measurement3) The performance of personal and business investments is measured as a percentage, returnon investment. What type of variable is return on investment?A. QualitativeB. ContinuousC. AttributeD. Discrete4) What type of variable is the number of robberies reported in your city?A. AttributeB. ContinuousC. DiscreteD. Qualitative5) What level of measurement is the number of auto accidents reported in a given month?A. NominalB. OrdinalC. IntervalD. Ratio6) The names of the positions in a corporation, such as chief operating officer or controller, areexamples of what level of measurement?A. NominalB. OrdinalC. IntervalD. Ratio7) Shoe sizes, such as 7B, 10D, and 12EEE, are examples of what level of measurement?A. NominalB. OrdinalC. IntervalD. Ratio8) Monthly commissions of first-year insurance brokers are $1,270, $1,310, $1,680, $1,380,$1,410, $1,570, $1,180, and $1,420. These figures are referred to as
A. a histogramB. raw dataC. frequency distributionD. frequency polygon9) A small sample of computer operators shows monthly incomes of $1,950, $1,775, $2,060,$1,840, $1,795, $1,890, $1,925, and $1,810. What are these ungrouped numbers called?A. HistogramB. Class limitsC. Class frequenciesD. Raw data10) The sum of the deviations of each data value from this measure of central location willalways be 0A. ModeB. MeanC. MedianD. Standard deviation11) For any data set, which measures of central location have only one value?A. Mode and medianB. Mode and meanC. Mode and standard deviationD. Mean and median12) A sample of single persons receiving social security payments revealed these monthlybenefits: $826, $699, $1,087, $880, $839, and $965. How many observations are below themedian?A. 0B. 1C. 2D. 313) A dot plot showsA. the general shape of a distributionB. the mean, median, and modeC. the relationship between two variablesD. the interquartile range14) The test scores for a class of 147 students are computed. What is the location of the testscore associated with the third quartile?A. 111B. 37C. 74D. 75%15) TheNationalCenterfor Health Statistics reported that of every 883 deaths in recent years, 24resulted from an automobile accident, 182 from cancer, and 333 from heart disease. Using therelative frequency approach, what is the probability that a particular death is due to anautomobile accident?A. 24/883 or 0.027B. 539/883 or 0.610C. 24/333 or 0.072D. 182/883 or 0.20616) If two events A and B are mutually exclusive, what does the special rule of addition state?A. P(A or B) = P(A) + P(B)
B. P(A and B) = P(A) + P(B)C. P(A and/or B) = P(A) + P(B)D. P(A or B) = P(A) - P(B)17) A listing of all possible outcomes of an experiment and their corresponding probability ofoccurrence is called aA. random variableB. probability distributionC. subjective probabilityD. frequency distribution18) The shape of any uniform probability distribution isA. negatively skewedB. positively skewedC. rectangularD. bell shaped19) The mean of any uniform probability distribution isA. (b - a)/2B. (a + b)/2C. Σ x/ ηD. nπ20) For the normal distribution, the mean plus and minus 1.96 standard deviations will includeabout what percent of the observations?A. 50%B. 99.7%C. 95%D. 68%21) For a standard normal distribution, what is the probability that z is greater than 1.75?A. 0.0401B. 0.0459C. 0.4599D. 0.959922) A null hypothesis makes a claim about aA) Population parameterB. sample statisticC. sample meanD. Type II error23) What is the level of significance?A. Probability of a Type II errorB. Probability of a Type I errorC. z-value of 1.96D. Beta error24) Suppose we test the difference between two proportions at the 0.05 level of significance. Ifthe computed z is -1.07, what is our decision?A. Reject the null hypothesisB. Do not reject the null hypothesisC. Take a larger sampleD. Reserve judgment25) Which of the following conditions must be met to conduct a test for the difference in twosample means?
A. Data must be at least of interval scaleB. Populations must be normalC. Variances in the two populations must be equalD. Data must be at least of interval scale and populations must be normal26) Which of the following statements about the two sample sizes is NOT true? Assume thepopulation standard deviations are equal.A. Sample A = 11; sample B = 13B. Sample A = 12; sample B = 14C. Sample A = 13; sample B = 13D. Sample A = 10; sample B = 1627) What is the chart called when the paired data (the dependent and independent variables)are plotted?A. Scatter diagramB. Bar chartC. Pie chartD. Histogram28) What is the variable used to predict the value of another called?A. Independent variableB. Dependent variableC. Correlation variableD. Variable of determination29) Twenty randomly selected statistics students were given 15 multiple-choice questions and15 open-ended questions, all on the same material. The professor was interested in determiningon which type of questions the students scored higher. This experiment is an example ofA. a one sample test of meansB. a two sample test of meansC. a paired t-testD. a test of proportions30) The measurements of weight of 100 units of a product manufactured by two parallelprocesses have same mean but the standard of process A is 15 while that of B is 7. What canyou conclude?A. The weight of units in process A are grouped closer than in process BB. The weight of units in process B are grouped closer than in process AC. Both processes are out of controlD. More data is needed to draw a conclusion