Answer:
The marketing department committed a Type I error because the marketing department rejected the null hypothesis when it was true. The probability of making a Type I error is 0.01.
Explanation:
Null Hypothesis: H₀ : µ = 58.58
Alternative Hypothesis: H₁ : µ> 58.58
A type I error is made by the marketing department if the null hypothesis is rejected when it is true and a type II error occurs, when the marketing department fails to reject the null hypothesis when it should be rejected.
The probability of making a Type I error is α, which is the level of significance you set for your hypothesis test, in our case 0.01 while the probability of making a Type II error is β, which depends on the power of the test.
Based on this we can therefore conclude that the marketing department committed a Type I error because the marketing department rejected the null hypothesis when it was true. The probability of making a Type I error is 0.01.