An automobile mileage study tested the following hypotheses. Hypothesis Conclusion H0: > 25 mpg .....Manufacturers claim

An automobile mileage study tested the following hypotheses.
Hypothesis Conclusion
H0: μ > 25 mpg .....Manufacturer’s claim supported
Ha: μ < 25 mpg .....Manufacturer’s claim rejected; average mileage per gallon less than stated
For σ = 3 and a .02 level of significance, what sample size would be recommended if the researcher wants an 80% chance of detecting that μ is less than 25 miles per gallon when it is actually 24?