The precision of a method is being established, and the following data are obtained: 22.23.22.18, 22.25, 22.09, and 22.17%. Is 22.09% a valid measurement at the 95% confidence level?

Can anyone help me with this? Please!

1. Consider a normal population distribution with the value of known?

a. What is the confidence level for the interval "X-bar "  

b. What is the confidence level for the interval "X-bar " ?

c. What value of in the Cl formula (7.5) results in a confidence level of 99.7%?

d. Answer the equation posed in part (c) for a confidence level of 75%? 

Use the confidence level and sample data to find a confidence interval for estimating the population μ. Round your

answer to the same number of decimal places as the sample mean.

Test scores: n = 104, x = 95.3, σ = 6.5; 99% confidence

The following data represent the asking price of a simple random sample of homes for sale. Construct a 99​% confidence interval with and without the outlier included. Comment on the effect the outlier has on the confidence interval.  

Construct a 99% confidence interval with the outlier included