1. Find the critical values,and, for c = 0.99 and n = 10.
2. Find the z-scores for which 98% of the distribution's area lies between -z and z.
3. Find the area under the standard normal curve to the left of z = 1.25.
4. IQ test scores are normally distributed with a mean of 100 and a standard deviation of 15. An individual's IQ score is found to be 120. Find the z-score corresponding to this value.
5. Use the standard normal distribution to find P(-2.50 < z < 1.50).
6. A random sample of 40 students has a test score with= 81.5. Assume the population standard deviation is 10.2. Construct the confidence interval for the population mean, if c = 0.90.
7. The monthly rents for studio apartments in a certain city have a mean of $920 and a standard deviation of $190. Random samples of size 30 are drawn from the population and the mean of each sample is determined.