Question

1. Which statement is incorrect?
A. The null hypothesis contains the equality sign
B. When a false null hypothesis is not rejected, a Type II error has occurred
C. If the null hypothesis is rejected, it is concluded that the alternative hypothesis is true
D. If we reject the null hypothesis, we cannot commit Type I error

2. When carrying out a large sample test of H0: μ ≤ 10 vs. Ha: μ > 10 by using a critical value approach, we reject H0 at level of significance α when the calculated test statistic is:
A. Less than zα
B. Less than - zα
C. Greater than zα
D. Greater than zα/2
E. Less than the p value

Answer 1

Answer 1

Option D is incorrect

We know that type I error is defined as the rejection of a true null

if we reject the null hypothesis, then there is a chance of making type I error, which is equal to the significance level

therefore, we can commit type I error only when reject the null hypothesis

Answer 2

For right tailed hypothesis

We reject the null hypothesis only when the z calculated is greater than z(alpha)

for one sided hypothesis, we keep alpha for finding critical values

therefore, option C is correct