Please use the following information to answer question 8a & 8b:

A random sample of n= 16 scores is obtained from a populationwith a mean of= 45. After a treatment is administered to the individuals in the sample, the sample mean is found to bex = 49.2.

8a. Assuming that the sample standard deviation iss= 8, calculate r² (MUST SHOW WORK FOR THIS PROBLEM).

Note: You must provide calculations for thet-observed statistic, in addition to r².

8b.Calculate Cohen's d to measure the size of the treatment effect (MUST SHOW WORK FOR THIS PROBLEM).

Please use the following information to answer question9a &9b:

A random sample of n= 16 scores is obtained from a populationwith a mean of= 45. After a treatment is administered to the individuals in the sample, the sample mean is found to bex = 49.2.

9a. Assuming that the sample standard deviation iss= 20, calculate r² (MUST SHOW WORK FOR THIS PROBLEM).

Note: You must provide calculations for the t-statistic, in addition tor².

9b.Calculate Cohen's d to measure the size of the treatment effect (MUST SHOW WORK FOR THIS PROBLEM).

Comparing your answers from 8 (a&b)and 9 (a&b),fill in the blank to properly describe how the variability of scores in the sample influence the measures of effect size.

10. Measures of effect size tend to ( ) with an increaseinsample variance.

Note:Your response for this should either be increase, decrease, or remains constant.