Answer:
95% confidence interval: (0.5717,0.8283)
Step-by-step explanation:
We are given the following in the question:
Sample size, n = 49
p = 70% = 0.7
Alpha, α = 0.05
The confidence interval can be calculated as:
[tex]p \pm z_{critical}\sqrt{\dfrac{p(1-p)}{n}}[/tex]
Putting the values, we get,
[tex]z_{critical}\text{ at}~\alpha_{0.05} = 1.96[/tex]
[tex]0.7 \pm 1.96(\sqrt{\dfrac{0.7(1-0.7)}{49}} ) = 0.7 \pm 0.1283 =(0.5717,0.8283)[/tex]
95% confidence interval: (0.5717,0.8283)