10. Standardized measures seem to indicate that the average level of anxiety has increased gradually over the past 50 years (Twenge, 2000). In the 1950s, the average score on the Child Manifest Anxiety Scale was 15.1. A sample of n 16 of today’s children produces a mean score of M 23.3 with SS 240.

a. Based on the sample, make a point estimate of the population mean anxiety score for today’s children.

b. Make a 90% confidence interval estimate of today’s population mean.