1. Imagine that a researcher wanted to know the average weight of 5thgrade boys in a high school. He randomly sampled 5 boys from that high school. Their weights were: 120 lbs., 99 lbs, 101 lbs, 87 lbs, 140 lbs. Whats the samplestandard deviation?

2. Imagine that a researcher wanted to know the average weight of 5thgrade boys in a high school. He randomly sampled 5 boys from that high school. Their weights were: 120 lbs., 99 lbs, 101 lbs, 87 lbs, 140 lbs. Whats thestandard error of the mean?

3. In order to test if there is a difference between means from two populations, which of following assumptions areNOTrequired?

a. The dependent variable scores must be a continuous quantitative variable.

b. The scores in the populations are normally distributed.

c. Each value is sampled independently from each other value.

d. The two populations have similar means

4. A researcher posed a null hypothesis that there was no significant difference between boys and girls on a standard memory test. He randomly sampled 100 girls and 120 boys in a community and gave them the standard memory test. The mean score for girls was 70 and the standard deviation of mean was 5.0. The mean score for boys was 65 and the standard deviation of mean was 6.0. Whats the absolute value of the difference between means?

5. A researcher posed a null hypothesis that there was no significant difference between boys and girls on a standard memory test. He randomly sampled 100 girls and 100 boys in a community and gave them the standard memory test. The mean score for girls was 70 and the standard deviation of mean was 5.0. The mean score for boys was 65 and the standard deviation of mean was 5.0. What is the standard error of the difference in means?

6. A researcher posed a null hypothesis that there was no significant difference between boys and girls on a standard memory test. He randomly sampled 100 girls and 100 boys in a community and gave them the standard memory test. The mean score for girls was 70 and the standard deviation of mean was 5.0. The mean score for boys was 65 and the standard deviation of mean was 5.0. Whats the t-value (two-tailed) for the null hypothesis that boys and girls have the same test scores?