A cheerleading squad received a mean rating (out of 100 possible points) of68 ± 9 (μ ± σ)in competitions over the previous three seasons. The same cheerleading squad performed in 16 local competitions this season with a mean rating equal to 71 in competitions. Suppose we conduct a one-independent sample z-test to determine whether mean ratings increased this season (compared to the previous three seasons) at a 0.05 level of significance.(a) State the value of the test statistic. (Round your answer to two decimal places.)z = State whether to retain or reject the null hypothesis. Retain the null hypothesis. Reject the null hypothesis. (b) Compute effect size using Cohen's d. (Round your answer to two decimal places.)d =