Here are summary statistics for randomly selected weights of newborn girls: n= 170, x= 26.9 hg, s= 6.7 hg. Construct a confidence interval estimate of the mean. Use a 99% confidence level. Are these results very different from the confidence interval 24.9 hg < µ <28.7 hg with only 16 sample values, x= 26.8 hg, and s = 2.6 hg?

The distribution of study times for first-year students follow a Normal distribution with a standard deviation σ = 48 minutes. Suppose a sample of 344 students found that the mean study time for these students was x¯= 170 minutes per week. Use this to find a 94.38% confidence interval to estimate the mean study time for all students. We are 94.38% confident that the mean study time for first-year students is between the following ( answer) minutes and  ( answer) minutes. The answer needs to be the mean study time for first-year students is between what amount of minutes and the following minutes.

Suppose you work for the Department of Environment and National Resources (DENR). You want to estimate, with 95% confidence, the mean length of all tilapia in a fish hatchery pond. You take a random sample of 10 tilapia and determine the average length is 10.5 inches and the sample standard deviation is 2.9 inches. Construct a confidence interval for this sample and interpret the result.

In the construction of an 88% Confidence Interval for a population mean u, a has the value of

We asked 41 people to report the number of cars they've ever owned. The results are a mean of 4.6 and a standard deviation of 1.3. Construct a 80% confidence interval.