Question

A national firm reports mean earnings of

$69 ± $12

(μ ± σ) per unit sold over the lifetime of the company. A competing company over the past 25 reporting periods had reported mean earnings equal to $71 per unit sold. Conduct a one-sample z-test to determine whether mean earnings (in dollars per unit) are larger (compared to that reported by the national firm) at a 0.05 level of significance.

(a) State the value of the test statistic z=

(b) Compute effect size using Cohen's d. (Round your answer to two decimal places.) d=

Answer 1