statistics
posted by jamie brice .
based on a random sample of 640 college students, the mean amount of sleep college students. construct a 95% confidence interval for the mean amount of sleep per night for college studenrs.

Formula:
CI95 = mean + or  1.96(sd/√n)
...where + or  1.96 represents the 95% interval using a ztable, sd = standard deviation, and n = sample size.
Fill in the data and calculate the interval. 
1) A sample of 49 observations is taken from a normal population. The sample mean is 55 and the sample standard deviation is 10. Determine the 99% confidence interval for the population mean.
2) The Fox TV network is considering replacing one of its primetime crime investigation shows with a new familyoriented comedy show. Before a final decision is made, network executives commission a sample of 400 viewers. After viewing the comedy, 250 indicated they would watch the new show and suggested it replace the crime investigation show.
A) Estimate the value of the population proportion.
B) Compute the standard error of the proportion.
C) Develop a 99% CI for the population proportion.
D) Interpret your findings