Questions: If n=16, x̄=32, and s=4, construct a confidence interval at a 98% confidence level. Assume the data came from a normally distributed population.
Give your answers to one decimal place.
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Transcript text: If $\mathrm{n}=16, \bar{x}(\mathrm{x}$-bar $)=32$, and $s=4$, construct a confidence interval at a $98 \%$ confidence level. Assume the data came from a normally distributed population.
Give your answers to one decimal place.
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Solution
Solution Steps
Step 1: Given Information
We are provided with the following parameters for constructing a confidence interval for the population mean:
To calculate the margin of error, we use the formula:
\[
\text{Margin of Error} = t \cdot \frac{s}{\sqrt{n}}
\]
where \( t \) is the critical value from the t-distribution for \( n - 1 = 15 \) degrees of freedom at the \( 98\% \) confidence level. From the calculations, we find:
\[
t \approx 2.6
\]
Thus, the margin of error is:
\[
\text{Margin of Error} = 2.6 \cdot \frac{4}{\sqrt{16}} = 2.6 \cdot \frac{4}{4} = 2.6
\]
Step 4: Construct the Confidence Interval
The confidence interval for the population mean is given by:
\[
\bar{x} \pm \text{Margin of Error}
\]
Substituting the values, we have:
\[
32 \pm 2.6
\]
This results in the interval:
\[
(32 - 2.6, 32 + 2.6) = (29.4, 34.6)
\]
Final Answer
The confidence interval for the population mean at a \( 98\% \) confidence level is:
\[
\boxed{(29.4, 34.6)}
\]