Determine the Sample Size Necessary for Estimating the Population Mean within a Specified Margin of Error
-The grade point averages for 10 randomly selected students in an algebra class with 125 students are listed below. What is the effect on the width of the confidence interval if the sample size is increased to 20 ?
$\begin{array} { l l l l l l l l l l } 2.0 & 3.2 & 1.8 & 2.9 & 0.9 & 4.0 & 3.3 & 2.9 & 3.6 & 0.8 \end{array}$
A) The width decreases.
B) The width increases.
C) The width remains the same.
D) It is impossible to tell without more information.

Question

Quizplus · Accepted Answer

Increasing the sample size generally results in a narrower confidence interval because the standard error of the mean decreases as the sample size increases.

Determine the Sample Size Necessary for Estimating the Population Mean 2.03.21.82.90.94.03.32.93.60.8\begin{array} { l l l l l l l l l l } 2.0 & 3.2 & 1.8 & 2.9 & 0.9 & 4.0 & 3.3 & 2.9 & 3.6 & 0.8 \end{array}2.0​3.2​1.8​2.9​0.9​4.0​3.3​2.9​3.6​0.8​

Determine the Sample Size Necessary for Estimating the Population Mean $\begin{array} { l l l l l l l l l l } 2.0 & 3.2 & 1.8 & 2.9 & 0.9 & 4.0 & 3.3 & 2.9 & 3.6 & 0.8 \end{array}$