Answer:
90% confidence interval: (70.41,86.89)
Step-by-step explanation:
We are given the following in the question:
Point estimate = 78.65
Margin of error, E = 8.24
Confidence level = 90%
Significance level = 10%
Formula:
[tex]\text{Point estimate} \pm \text{Margin of error}[/tex]
Putting the values, we get,
[tex]z_{critical}\text{ at}~\alpha_{0.10} = \pm 1.64[/tex]
[tex]78.65 \pm 8.24 = (70.41,86.89)[/tex]
(70.41,86.89) is the required 90% confidence interval.
