Questions: Refer to the accompanying data display that results from a simple random sample of times (minutes) between eruptions of the Old Faithful geyser. The confidence level of 95% was used. Complete parts (a) and (b) below.
TInterval
(85.74,91.76)
x̄=88.75
Sx=8.897431411
n=36
a. Express the confidence interval in the format that uses the "less than" symbol. Round the confidence interval limits given that the original times are all rounded to one decimal place.
min <μ< min
(Round to two decimal places as needed.)
Transcript text: Refer to the accompanying data display that results from a simple random sample of times (minutes) between eruptions of the Old Faithful geyser. The confidence level of $95 \%$ was used. Complete parts (a) and (b) below.
TInterval
\[
\begin{array}{l}
(85.74,91.76) \\
\bar{x}=88.75 \\
S x=8.897431411 \\
n=36
\end{array}
\]
a. Express the confidence interval in the format that uses the "less than" symbol. Round the confidence interval limits given that the original times are all rounded to one decimal place.
$\square$
$\square$
$\min <\mu<$ min
(Round to two decimal places as needed.)
Solution
Solution Steps
Step 1: Calculate the Margin of Error
To determine the margin of error for the confidence interval, we use the formula:
\[
\text{Margin of Error} = \frac{Z \times \sigma}{\sqrt{n}}
\]
where:
\( Z = 1.96 \) (the Z-score for a 95% confidence level),
\( \sigma = 8.897431411 \) (the sample standard deviation),