Sign in or 
Share this
Showing 2 posts
|
tutoringcenter |
Practice Quiz 2
Mar 15 2011, 1:01 PM EDT
| Post edited: Mar 15 2011, 1:02 PM EDT
1. Consider a sample with a mean of 500 and a standard deviation of 100. What are the z-scores for the following data values: 520, 650, 500, 450, and 280?2. Consider that the mean price of a customized wooden, shingled backyard structure is $3100 and the standard deviation is $1200. a. What is the z-score for a backyard structure costing $2300? b. What is the z-score for a backyard structure costing $4900? c. Determine whether or not the costs above are outliers. 3. The results of a national survey showed that on average, adults sleep 6.9 hours per night. Suppose that the standard deviation is 1.2 hours. a. Use Chebyshev’s theorem to calculate the percentage of individuals who sleep between 4.5 and 9.3 hours. b. Assume that the number of hours of sleep follows a bell-shaped distribution. Use the empirical rule to determine the percentage of individuals who sleep between 4.5 and 9.3 hours. 4. Show the five-number summary and determine the upper and lower limits for the following data: 5, 15, 18, 10, 8, 12, 16, 10, 6. Do you find this valuable?
Keyword tags:
None
|
|
tutoringcenter |
1. ANSWERS
Mar 15 2011, 1:02 PM EDT
Answers1. z-scores are: 0.2, 1.5, 0, -0.5, -2.2 2. z-score for $2300 is -0.67, z-score for $4900 is 1.5, neither is outlier 3. 75% using Chebyshev’s, 95% using empirical rule 4. 5-number summary is 5, 8, 10, 15, 18 upper limit is 25.5, lower limit is -2.5 Do you find this valuable? |
