It is well documented that cholesterol over 200 is a risk factor in developing heart disease for both men and women. Younger men are known to have higher cholesterol levels than younger women; however, beyond age 55, women are more likely to have higher cholesterol levels. A recent college graduate working at a local blood lab has access to the cholesterol data of 50 men and 50 women in the 20–40 age groups. The accompanying table shows a portion of the cholesterol data; the complete data set, labeled Cholesterol_Levels, can be found on the text website.

MenWomen

181.........178

199.........193

: ......... :

190.........182

Use the critical value approach, at the 1% significance level, to determine if there are any differences in the mean cholesterol levels for men and women in the age group. It is fair to assume that the population variances for men and women are equal. Describe your steps clearly.