The Lifetime of a Squirrel Follows a Normal Distribution with Mean

Multiple Choice

The lifetime of a squirrel follows a normal distribution with mean μ months and a standard deviation $\sigma$ =7 months.To test the alternative hypothesis that μ > 40, 25 squirrels are randomly selected.The null hypothesis is rejected when the sample mean is bigger than 43.Assuming that μ=45, the probability of type II error is approximately _________.

A) 0.076
B) 0.016
C) 0.05
D) 0.011
E) 0.983