15. A study is conducted to compare mean cholesterol levels for individuals following a low-carbohydrate diet for at least 6 months to individuals following a conventional (low-fat, low-calorie) diet for at least 6 months. The data are summarized in Table 7-59. Test if there is a significant difference in mean cholesterol levels between the diet programs using a 5% level of significance.

Table 7-59: Cholesterol Levels by Treatment

Diet Program Sample Size Mean Cholesterol Std Dev Cholesterol Low Carbs 50 225.4 24.5

Conventional 75 203.8 21.6