A company offers all its employees a physical each year. The blood cholesterol level for men aged 30 to 39 has a standard deviation of 12 mg/dL. For women in the same age group, the standard deviation is 24 mg/dL. A sample of 20 men aged 30 to 39 had a mean cholesterol level of 204 mg/dL.
A sample of 28 women aged 30 to 39 had a mean cholesterol level of 210 mg/dL.

What is the probability of observing these sample means if the population means are the same?

0.2542
0.1271
1.14
-1.14