Question 1 In a cross tabulation Answer both variables must be categorical both variables must be quantitative one variable must be categorical and the other must be quantitative either or both variables can be categorical or quantitative Question 2 In order to test the hypotheses H0: m ? 100 and Ha: m > 100 at an a level of significance, the null hypothesis will be rejected if the test statistic z is Answer ? za 5 H0: m > 5 Ha: m £ 5 H0: m ³ 5 Ha: m < 5 Question 13 If the data distribution is symmetric, the skewness is Answer 0 .5 1 None of the other answers is correct. Question 14 Exhibit 10-5 The following information was obtained from matched samples. Individual Method 1 Method 2 1 7 5 2 5 9 3 6 8 4 7 7 5 5 6 Refer to Exhibit 10-5. The 95% confidence interval for the difference between the two population means is Answer -3.776 to 1.776 -2.776 to 2.776 -1.776 to 2.776 0 to 3.776 Question 15 Exhibit 2-1 The numbers of hours worked (per week) by 400 statistics students are shown below. Number of hours Frequency 0 – 9 20 10 – 19 80 20 – 29 200 30 – 39 100 Refer to Exhibit 2-1. The percentage of students who work at least 10 hours per week is Answer 50% 5% 95% 100% Question 16 Exhibit 10-5 The following information was obtained from matched samples. Individual Method 1 Method 2 1 7 5 2 5 9 3 6 8 4 7 7 5 5 6 Refer to Exhibit 10-5. If the null hypothesis is tested at the 5% level, the null hypothesis Answer should be rejected should not be rejected should be revised None of these alternatives is correct. Question 17 In a sample of 800 students in a university, 160, or 20%, are Business majors. Based on the above information, the school’s paper reported that “20% of all the students at the university are Business majors.” This report is an example of Answer a sample a population statistical inference descriptive statistics Question 18 The function that defines the probability distribution of any continuous random variable is a Answer normal function uniform function Both the normal function and the uniform function are correct. probability density function Question 19 Excel provides functions for computing the Answer mean median mode Excel provides functions for all of these. Question 20 The basis for using a normal probability distribution to approximate the sampling distribution of and is Answer Chebyshev’s theorem the empirical rule the central limit theorem Bayes’ theorem