The scores of a certain population on the wechsler intelligence scale for children (wisc) are thought to be normally distributed with mean m and standard deviation s = 10. a simple random sample of 25 children from this population is taken and each is given the wisc. the mean of the 25 scores is x = 104.32. based on these data, a 95% confidence interval for m is a) 104.32 â± 0.78. b) 104.32 â± 3.29. c) 104.32 â± 3.92. d) 104.32 â± 19.60