# Confidence Interval Multiple Choice

See the attached file.

6. 100 employees were randomly selected and the mean time on work per week 41 hours with std deviation of 5 hrs. The 95% confidence interval for the mean time for all employees on work per week was:

(a)(40.02,41.98)

(b)(40.18,41.82)

(c)(1.88,8.12)

(d)(2.75,7.25)

For questions 7 to 9:

Let X be a random variable with mean 200 and std deviation of 25. Find the following x values:

7. The x value such that the area under the normal curve to the left of x is 0.6330.

(a)208.5

(b)241.125

(c) 241.75

(d) 250

8. The x value such that the area under the normal curve to the right of x is 0.5

(a)208.5

(b)241.125

(c) 241.75

(d) 250

9. The x value such that the area under the normal curve between 200 and x is 0.4525(x>200)

(a)208.5

(b)241.125

(c) 241.75

(d) 250.

https://brainmass.com/statistics/mean/confidence-interval-multiple-choice-181305

#### Solution Summary

The solution determines the confidence interval in the different questions with brief explanations.