To investigate the effect of fruit on cholesterol, 40 participants were randomised into two treatment groups (20 in each). Both groups were given the same information about healthy diet and activity, BUT only one group was given 75 grams of dried apple as well to consume daily. The cholesterol level for every participant was measured (in mmol/L) before the study, and six months later, and the % change was calculated. 

Choose the most appropriate statistical method to decide if eating apple has any effect on the change in cholesterol: