Suppose that a sample of 39 employees at a large company were surveyed and asked how many hours a week they thought the company wasted on unnecessary meetings. The mean number of hours these employees stated was 12.4 with a standard deviation of 5.1. Calculate a 99% condence interval to estimate the mean amount of time all employees at this company believe is wasted on unnecessary meetings each week. (hint: population standard deviation is unknown)
Added by Albert F.
Step 1
We are given the sample mean ($\bar{x}$) as 12.4, the sample standard deviation (s) as 5.1, and the sample size (n) as 39. Show more…
Show all steps
Close
Your feedback will help us improve your experience
Robin Corrigan and 70 other Intro Stats / AP Statistics educators are ready to help you.
Ask a new question
Labs
Want to see this concept in action?
Explore this concept interactively to see how it behaves as you change inputs.
Key Concepts
Recommended Videos
suppose a large Labor union wishes to estimate the mean number of hours per month a union member is absent from work. The union decides to sample 120 of its members at random and monitor they’re working time for one month. At the end of the month, the total number of hours absent from the work is required for each employee. If the mean and standard deviation of the sample or 9.6 hours and 6.4 hours respectively find a 95% confidence interval for for the true mean number of hours absent per month per employee. round to four decimal places
Sri K.
Suppose that a sample of 42 students of a university were surveyed and asked how many hours a week they thought they spent on studying. The mean number of hours these students stated was 13.5 with a standard deviation of 4.8. Calculate a 99% confidence interval to estimate the mean amount of time all students of the university believe they spend studying in a week.
Robin C.
(a) Employees in a large manufacturing plant worked an average of 62 hours of overtime last year, with standard deviation of 15 hours. The human resources director selects a simple random sample of 36 employees to engage in discussion with regard to the company’s overtime policy. What is the probability that the average number of overtime hours last year for member of this sample would have been less than 65 hours? (b) A fast food outlet claims that the mean waiting time in line is less than 5.1 minutes. A random sample of 19 customers has a mean of 4.8 minutes with a standard deviation of 0.6 minute. If α = 0.05, test the fast food outlet’s claim.
Kari H.
Recommended Textbooks
Elementary Statistics a Step by Step Approach
The Practice of Statistics for AP
Introductory Statistics
Transcript
18,000,000+
Students on Numerade
Trusted by students at 8,000+ universities
Watch the video solution with this free unlock.
EMAIL
PASSWORD