1. An SRS of 20 third grade children is selected in Chicago and each is given a test to measure their reading ability. We are interested in a 90% confidence interval for the population mean score. In the sample, the mean score is 64 points and the standard deviation is 12 points. The margin of error associated with the confidence interval is
A. 2.68 points.
B. 4.64 points.
C. 5.62 points.
2. We wish to see if the dial temperature for a certain model oven is properly calibrated. Four ovens of a certain model are selected at random. The dial on each is set to 300° F and after one hour, the actual temperature of each is measured. The temperatures measured are 305°, 310°, 300°, and 305°. Assuming that the actual temperatures for this model when the dial is set to 300° are Normally distributed with mean μ, we test whether the oven is properly calibrated by testing the hypotheses
H0: μ = 300, Ha: μ ≠ 300.
Based on the data, the P-value for this test is
A. between 0.10 and 0.05.
B. between 0.05 and 0.025.
C. between 0.025 and 0.01.
3. It has been claimed that women live longer than men; however, men tend to be older than their wives. Ages of sixteen husbands and wives from England were obtained. The null hypothesis of equality of means is rejected. What conclusion can be made from this study?
A. English husbands are older than their wives.
B. Husbands are older than their wives.
C. The sample was too small. No conclusions can be made.