# 10 mcqs in statistics …

1. Assume that the data has a normal distribution and the number of observations is greater than fifty. Find the critical z value used to test a null hypothesis. = 0.09 for a right-tailed test. (Points : 5) ±1.96 1.34 ±1.34 1.96

2. Find the value of the test statistic z using z = The claim is that the proportion of drowning deaths of children attributable to beaches is more than 0.25, and the sample statistics include n = 681 drowning deaths of children with 30% of them attributable to beaches. (Points : 5) 3.01 2.85 -2.85 -3.01

3. Use the given information to find the P-value. Also, use a 0.05 significance level and state the conclusion about the null hypothesis (reject the null hypothesis or fail to reject the null hypothesis). The test statistic in a left-tailed test is z = -1.83. (Points : 5) 0.0672; reject the null hypothesis 0.0336; reject the null hypothesis 0.9664; fail to reject the null hypothesis 0.0672; fail to reject the null hypothesis

4. Use the given information to find the P-value. Also, use a 0.05 significance level and state the conclusion about the null hypothesis (reject the null hypothesis or fail to reject the null hypothesis).

With H1: p < 3/5, the test statistic is z = -1.68

p- value = 0.0465, Reject the null hypothesis

5. Find the critical value or values of based on the given information. H1: > 26.1 n = 9 = 0.01 (Points : 5) 1.646 21.666 20.090 2.088

6. Find the number of successes x suggested by the given statement. A computer manufacturer randomly selects 2850 of its computers for quality assurance and finds that 1.79% of these computers are found to be defective. (Points : 5) 51 56 54 49

7. Assume that you plan to use a significance level of alpha = 0.05 to test the claim that p1 = p2, Use the given sample sizes and numbers of successes to find the pooled estimate Round your answer to the nearest thousandth. n1 = 570; n2 = 1992 x1 = 143; x2 = 550 (Points : 5) 0.541 0.270 0.520 0.216

8. Assume that you plan to use a significance level of alpha = 0.05 to test the claim that p1 = p2. Use the given sample sizes and numbers of successes to find the z test statistic for the hypothesis test. A report on the nightly news broadcast stated that 10 out of 108 households with pet dogs were burglarized and 20 out of 208 without pet dogs were burglarized. (Points : 5) z = -0.041 z = -0.102 z = 0.000 z = -0.173

9. Assume that you plan to use a significance level of alpha = 0.05 to test the claim that p1 = p2. Use the given sample sizes and numbers of successes to find the P-value for the hypothesis test. n1 = 50; n2 = 75 x1 = 20; x2 = 15 (Points : 5) 0.0032 0.0146 0.1201 0.0001

10. Construct the indicated confidence interval for the difference between population proportions p1 – p2. Assume that the samples are independent and that they have been randomly selected. x1 = 61, n1 = 105 and x2 = 82, n2 = 120; Construct a 98% confidence interval for the difference between population proportions p1 – p2. (Points : 5) 0.456 < p1 – p2 < 0.707 0.432 < p1 – p2 < 0.730 -0.228 < p1 – p2 < 0.707 -0.252 < p1 – p2 < 0.047