Type 1 and Type 2 Errors in Hypothesis Testing

A Type I error occurs if we reject the null hypothesis when in fact it is true.
The probability of a Type I error is exactly equal to α, the significance level of the test.
A Type II error occurs if we accept the null hypothesis when it is not true.
To find the probability of a Type II error, we
1. Find the critical value for rejecting H_0 assuming μ=μ_0
2. Find the probability that H_0 is not rejected, given the true mean μ=μ_1.