Researchers were interested in comparing the long-term psychological effects of dieters on

a high-carbohydrate, low-fat (LF) diet with those on a high-fat, low-carbohydrate (LC) diet. A total of 106 overweight and obese individuals were randomly assigned to one of these two energy-restricted diets. At 52 weeks a total of 32 LC dieters and 33 LF dieters remained. Mood was assessed using a total mood disturbance score (TMDS), where a lower score is associated with a less negative mood. A summary of these results are:

Group Sample size Sample mean Sample standard deviation

LC 32 47.3 28.3

LF 33 39.3 25.8

Is there a difference in the TMDS at week 52 between the two groups of dieters? Conclude and use a significance level of 0.05. Notice that the test-statistic for this problem would be:

=47.3 39.3/ (28.3²/32)+ (25.8²/33) =1.1899