Example 125

Example 125: A researcher predicts that a low carbohydrate diet will result in a loss of lean muscle mass of 3.5 pounds of muscle per ten pounds of overall weight loss.  A recent study that looked at the effects of restricting carbohydrate intake on weight loss involved reducing total calorie intake by 600 calories per day while following a diet that had the following macro nutrient ratios: 38:30:32 (percent of carbohydrate to protein to fat).  Thirty-two overweight men followed the diet for 16 weeks.  The average loss of lean mass (for every ten pounds of overall weight loss) was 3.3 pounds.  The standard deviation for the amount of lean mass lost per ten pounds of weight loss was 5.1 pounds.  Use the p-value method to test the researcher’s prediction at the 2% significance level.