Cathy wants to determine the type of slimming products that give better results in losing weight. She is considering two types of slimming products—pills and food supplements. She assigned two groups of people, having a similar body size, to use these products. After a month of treatment, she finds that those using the pills lost an average of 8 kg, with a standard deviation of 2 kg. Those who took the food supplements lost an average of 9 kg with the standard deviation of 3 kg.

a. Calculate the coefficient of variation for both types of slimming product.

b. Based on your findings in part

a, determine which slimming product is more efficient in losing weight.

c. Assuming the weight lost produces a bell-shaped curve, determine the percentage of people who lost more than 11 kg for both groups.