The mean height of 61 males from the same state was 68.2 inches with an estimated standard deviation of 2.5 inches, while 61 males from another state had a mean height of 67.5 inches with an estimated standard deviation of 2.8 inches. The heights are normally distributed. Test the hypothesis that males from the first state are taller than males from the second state.

a) Use a level of significance of 5%.

b) Use a level of significance of 10%.