Question

1. An IQ test is designed so that the mean is 100 and the standard deviation is 24 for the population of normal adults. Find the sample size necessary to estimate the mean IQ score of statistics such that it can be said with 90% confidence that the sample mean is within 4 IQ points of the true mean. Assume that o=24 and determine the required sample size. Then determine if the required sample size is a reasonable sample size for a real world calculation.

2. The ages of a group of 135 randomly selected fenal adults have a standard deviation of 18.5 years. Assume that the ages of female statistics students have less variation than ages of females in the general population, so let o=18.5 years for the sample size calculation. How many female statistics student ages must be obtained in order to estimate the mean of all female statistics students? Assume that we want 98% confidence that the sample mean is within one-half year of the population mean. Does it seem reasonable to assume that the ages of female statistics students have less variation than ages of females in the general poulation?

3. The pulse rates of 142 randomly selected males very from a low of 36 bpm to a high of 112 bpm. Find the minimum sample size required to estimate the mean pulse rate of adult males. Assume that we want 98% confidence that the sample mean is within 4 bpm of the population mean.

Answer 1