7.56 Basic concepts. For each of the following, answer the question and give a short explanation of your reasoning.

1. (a) A 95% confidence interval for the difference between two means is reported as . What can you conclude about the results of a significance test of the null hypothesis that the population means are equal versus the two-sided alternative?

2. (b) Will larger samples generally give a larger or smaller margin of error for the difference between two sample means?