Question

Algebra 2

Answer 1

Answer:

Step-by-step explanation:

n=sample size =200

Mean = x bar = 55 hours

Std deviation (Population) = 7 hours

For 99% confidence level

Z critical value = 2.58

Margin of error = ±2.58(std error)

Std error = $\frac{7}{\sqrt{n} } =0.495$

Hence margin of error = ±0.495(258)=1.28

Confidence interval = (55-1.28, 55+1.28) = (53.72, 56.28)

~(53.73, 56.27)

Hence option A

Answer 2

MOE = +\- 1.27
Confidence Interval is 53.73 to 56.27