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 =

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Answer:

a = 1.33

b = 0.33

Step-by-step explanation:

m1 = 71

m2 = 68

But z=(m1 - m2)/( sd/√n)

where n = sample size

Z = (71 -68)/(9/√16)

Z = 3/2.25

Z = 1.33

Value of test statistic is 1.33

We reject the null hypothesis since 1.33 > 0.05

Cohen's d = m1 - m2/ sd

= 71 - 68 /9

= 3/9

= 0.33