1. What sample size is required for a maximum error of estimation of 10 for a population whose standard deviation is 40 using a confidence interval of 0.95? How much larger must the sample size be if the maximum error is to be 5?
2. The following sample was taken from a normally distributed population with a known standard deviation σ = 4. Test the hypothesis that the mean μ = 20 using a level of significance of 0.05 and the alternative that μ > 20:
23, 32, 22, 31, 27, 25, 21, 24, 20, 18.