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?

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]±*(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!

step-by-step explanation:

first you will have to convert 3/4 into a decimal

which is .75

then you will have to divide 1.5 by .75

which is 2

no you have to divide

answer:   rotate 270° clockwise about (7, 1) and reflect across the line x = 7

step-by-step explanation:

because i took test