36) What distribution must be used when computing confidence intervals for variances and standard deviations? A) Chi-square B) Uniform C) Normal D) Sigma 36) 37) A chi-square variable cannot be negative, and the distributions are positively skewed. A) True B) False 37) 38) The area under each chi-square distribution is equal to 38) A) -1 B) 100 C) 0 D) 1 39) In order to find confidence intervals for variances and standard deviations, one must assume that the variable is 39) A) uniform B) continuous C) normally distributed D) random 40) The formula for the confidence interval for a standard deviation is (7-1)52 (n-1)s2 (n+1)s2 n+1)s2 2 2 2 2 X right X left X right X left A)