Question

Use the sample information

x¯= 40, σ = 7, n = 13 to calculate the following confidence intervals for μ assuming the sample is from a normal population.

(a) 90 percent confidence. (Round your answers to 4 decimal places.)
  
The 90% confidence interval is from ___ to___

(b) 95 percent confidence. (Round your answers to 4 decimal places.)
  
The 95% confidence interval is from ___ to____

(c) 99 percent confidence. (Round your answers to 4 decimal places.)
  
The 99% confidence interval is from ____to____

(d) Describe how the intervals change as you increase the confidence level.
  

1)The interval gets narrower as the confidence level increases.

2)The interval gets wider as the confidence level decreases.

3)The interval gets wider as the confidence level increases.

4)The interval stays the same as the confidence level increases.

Answer 1