Repeat parts (a)-(c) of Exercise 9.194 for a sample size of 15. Compare your power curves for the two sample sizes, and explain the principle being illustrated.
The null and alternative hypotheses obtained in Exercise 9.18 on page 375 are, respectively,
H0: μ = 55 years old
Ha: μ < 55 years old,
Where μ is the mean age at diagnosis of all people with early-onset dementia.
i. σ = 6.8
ii. α = 0.01
iii. n = 21
iv. μa = 47, 48, 49, 50, 51, 52, 53, 54