Question

Computing a confidence interval Suppose parts (a) through (d) below provide results for a study on the role of calcium in reducing the symptoms of PMS. For each of the parts, compute an approximate 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. Suppose there were 228 participants in the placebo group and 212 in the calcium-treated group. (Round your answers to two decimal places.) (a) mood swings: placebo = 0.70 +0.78; calcium = 0.50 +0.51 to (b) crying spells: placebo = 0.39 + 0.57; calcium = 0.21 + 0.40 to (c) aches and pains: placebo = 0.43 +0.60; calcium = 0.39 +0.43 to (d) craving sweets or salts: placebo = 0.60 + 0.75, calcium = 0.44 +0.65 to Need Help? Read It Watch It Talk to a Tutor

Answer 1

Solution: a) Herre given, F1=0.70, 72 -0.50 SI -0.78, S2=0.51 ni228,02=212 ca= st S2 Z2l2 = Zo.o5 ne 1.96 2 -(0.70 -0.50) = (x1 - 52) + Za trage =10.0776, 0.3223 0.78)2,0.51) + 228 212 228 212 b) CB = (0.39 -0.21) +1.96 J 6.5 732 760.409% es -([0-184, C-295) (0.43 -0.39) -[-0.0570, 0-1570) (0.60)² + (0.43)² c) CI- 3-0.39) 1.96 228 212 I = d) c2 = (0.60 -0.44) + 1.96 16.75)? 665) + 228 212 CI= [0:0291 0291, 0.2908 다. ノ