Question

The water diet requires one to drink two cups of water every half hour from when one gets up until one goes to bed, but otherwise allows one to eat whatever one likes. Four adult volunteers agree to test the diet. They are weighed prior to beginning the diet and after six weeks on the diet. The weights ( in pounds) are Person 1 2 3 4 Weight before diet 180 125 240 150 Weight after diet 170 130 215 152 For the population of all adults, assume that the weights loss after six weeks on the diet ( weight before beginning the diet---weight after six weeks on the diet) is Normally distributed with mean μ. a. Test the hypothesis if the diet leads to weight loss. b. Construct a 95% confidence interval for the mean difference.

Answer 1

We have for difference data,          
              
Sample mean =7      
Sample standard deviation =13.64  
Sample size =4      
Level of significance=0.05      
Degree of freedom =3      
              
t critical value is (by using t table)=3.18  
              
Confidence interval formula for paired t test.