For the provided samplemean, samplesize, and population standarddeviation, complete parts(a) through(c) below.

x=30, n=100, =2

a. Find a95% confidence interval for the population mean.

The95% confidence interval is from 29.61to 30.39

(Round to two decimal places asneeded.)

b. Identify and interpret the margin of error.?

(Round to two decimal places asneeded.)

C. What is the length of the confidenceinterval?

A random sample of 20 recent weddings in a country yielded a mean wedding cost of

$26,380.58. Assume that recent wedding costs in this country are normally distributed with a standard deviation of $8000. Complete partsthrough

a. Determine a95% confidence interval for the meancost, , of all recent weddings in this country.?

For the followingcase, assume that the population standard deviation is known and decide whether use of thez-interval procedure to obtain a confidence interval for the population mean is reasonable. Explain your answer. The variable under consideration is very close to being normallydistributed, and the sample size is 10.

Choose the correct answer below.

A. It is reasonable to use thez-interval procedure in this case since both the sample is large(size 10 orgreater) and the variable under consideration is very close to being normally distributed.

B. It is not reasonable to use thez-interval procedure in this case because the sample is too small(size less than15).

C. It is reasonable to use thez-interval procedure in this casesince, although the sample is small(size less than15), the variable under consideration is very close to being normally distributed.

D.It is not reasonable to use thez-interval procedure in this case since it is very likely that with such a small sample size that there will be outliers in the sample. Knowing that the variable under consideration is very close to being normally distributed does not mean the sample is.