Question

Chapter 6, Section 2-CI, Exercise 083 Use the t-distribution to find a confidence interval for a mean u given the relevant sample results. Give the best point estimate for u, the margin of error, and the confidence interval. Assume the results come from a random sample from a population that is approximately normally distributed. A 90% confidence interval for u using the sample results i = 3.2, s = 0.2, and n = 100 Round your answer for the point estimate to one decimal place, and your answers for the margin of error and the confidence interval to two decimal places. point estimate = margin of error= The 90% confidence interval is

Answer 1

sample mean 'x̄=	3.200
sample size   n=	100.00
sample std deviation s=	0.200
std error 'sx=s/√n=	0.020

for 90% CI; and 99 df, value of t=		1.6600
margin of error E=t*std error    =		0.03
lower bound=sample mean-E =		3.17
Upper bound=sample mean+E =		3.23
from above 90% confidence interval for population mean =(3.17,3.23)

from above:

   point estimate =3.2

margin of error =0.03

The 90% confidence interval is =3.17 to 3.23