a) Parameter, population standard deviation σ = 13.0
__
Sample statistics n=36 x = 58.5
b)The margin of error E is 4.2467
c)The confidence interval is (54.2533, 62.7467)
d) we are 95% confident that the mean age of US millionaires is between (54.2533 , 62.7467)
EXPLANATION
From the given question;
a) The given Parameter or (statistics)
Parameter, population standard deviation σ = 13.0
__
Sample statistics n=36 x =58.5
b) The margin of Error E can be calculated using the formula below:
Substitute the the values into the formula and simplify.
Hence, the margin of error E is 4.2467
c) The confidence interval can be calculated using the formula below:
Substitute the values and simplify.
Hence, the confidence interval is (54.2533, 62.7467)
d)Conclusion
Hence, we are 95% confident that the mean age of US millionaires is between (54.2533 , 62.7467)