15. Parts a–d below provide additional results for Case Study 21.1. For each of the parts, compute a 95% confidence interval for the difference in mean symptom scores between the placebo and calcium-treated conditions for the symptom listed. In each case, the results given are mean  standard deviation. There were 228 participants in the placebo group and 212 in the calcium-treated group.

a. Mood swings: placebo  0.70  0.75; calcium  0.50  0.58

b. Crying spells: placebo  0.37  0.57; calcium  0.23  0.40

c. Aches and pains: placebo  0.49  0.60; calcium  0.31  0.49

d. Craving sweets or salts: placebo  0.60  0.78; calcium  0.43  0.64