Answer:
a) (233.09,271.80)
b) Yes
Step-by-step explanation:
We are given the following information:
Population mean = $215.60
Sample mean = $252.45
Sample standard deviation = $77.50.
n = 64
Formula:
[tex]\bar{x} \pm t_{critical}\frac{s}{\sqrt{n}}[/tex]
Putting the values, we get,
[tex]t_{critical}\text{ at degree of freedom 63 and}~\alpha_{0.05} = 1.998[/tex]
[tex]252.45 \pm 1.998(\frac{77.50}{\sqrt{64}} ) = 252.45 \pm 19.355 = (233.09,271.80)[/tex]
b) The mean amount spent per day by families visiting Niagara Falls differs from the mean reported by the American Automobile Association because the confidence interval lies above $215.60