A random sample of 10 single mothers was drawn from an Obstetrics Clinic. Their ages are 22, 17, 27, 20, 23, 19, 24, 18, 19, and 24 years.

a.) Estimate the population mean with 90% confidence.

b.) Test to determine if we can infer at the 5% significance level that the population means is not equal to 20.