Question

Announcements for 84 upcoming engineering conferences were randomly picked from a stack of IEEE Spectrum magazines. The mean length of the conferences was 3.94 days, with a standard deviation of 1.28 days. Assume the underlying population is normal. What is the error bound of 95% confidence interval for the population mean length of engineering conferences? Construct a 95% confidence interval for the population mean length of engineering conferences. What is the lower bound? Construct a 95% confidence interval for the population mean length of engineering conferences. What is the upper bound?

Answer 1

Answer:

Step-by-step explanation:

Hello!

You need to construct a 95% CI for the population mean of the length of engineering conferences.

The variable has a normal distribution.

The information given is:

n= 84

x[bar]= 3.94

δ= 1.28

The formula for the Confidence interval is:

x[bar]±$Z_{1-\alpha/2}$*(δ/n)

Lower bound(Lb): 3.698

Upper bound(Ub): 4.182

Error bound: (Ub - Lb)/2 = (4.182-3.698)/2 = 0.242

I hope it helps!