The events for which the null hypothesis is rejected are called the critical region. Statisticians will not nomally reject a null hypothesis unless the probability of an outcome occurring in the critical region is less than 0.05. This means that data would appear by chance in the critical region even when H0 is true less than 5% of the time. This is referred to as a 5% significance level.

a. Write down the significance level of your test.

b. Find the significance level for a different choice of critical region. Would you prefer this one over the one chosen previously? Justify your answer.

c. Comment on the symmetry of your critical regions and discuss whether they have to be symmetrical.