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Unformatted text preview: Grading Summary
These are the automatically computed results of your exam. Date Taken: Grades for essay questions, and comments from your Time Spent:
instructor, are in the "Details" section below. Points Received: Question Type:
Multiple Choice Grade Details # Of Questions:
37 min , 21 secs 19 / 20 (95%) # Correct:
19 1. Question : A new extendedlife light bulb has an average service life of 750 hours, with a standard deviation of 50 hours. If the service life of these light bulbs approximates a normal distribution, about what percent of the distribution will be between 600 hours and 900 hours? Student Answer: 95% 68% 34% 99.7% Points Received: 1 of 1 Comments: 2. Question : Which of the following is NOT true regarding the normal distribution? Student Answer: Mean, median and mode are all equal It has a single peak It is symmetrical The points of the curve meet the Xaxis at z = 3 and z = 3 Points Received: 1 of 1 Comments: 3. Question : The mean amount of gasoline and services charged by Key Refining Company credit customers is $70 per month. The distribution of amounts spent is approximately normal with a standard deviation of $10. What is the probability of selecting a credit card customer at random and finding the customer charged between $70 and $83? Student Answer: 0.1962 * Times are displayed in (GMT06:00) Central Time (US & Canada) ...
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This note was uploaded on 10/07/2011 for the course EC 315 taught by Professor Barcus during the Spring '10 term at Park.
- Spring '10