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

Astudent is determining the influence of different types of food on the growth rate of spiders. she feeds one group of spiders two caterpillars twice a week. the other group received similarly-sized beetles twice a week. she records the amount of time required for individuals to reach sexual maturity. her hypothesis is that the spiders feeding on caterpillars will have a faster growth rate because caterpillars have a higher protein content compared to beetles. in this experiment, what is the dependent variable? spiders assigned to different feeding groups. time required to reach sexual maturity number of prey items fed twice a week. growth rates of each group.