Normal Probability Distributions/Introduction to Normal Distributions and the Standard Normal Curve Question 41 Manufacturer Claims

You work for a consumer watchdog publication and are testing the advertising claims of a lightbulb manufacturer.  The manufacturer claims that the life span of the bulb is normally distributed, with a mean of 2000 hours and a standard deviation of250 hours.  You test 20 lightbulbs and get the following life spans.

2210 2406 2267 1930 2005 2502 1106 2140 1949 1921
2217 2121 2004 1397 1659 1577 2840 1728 1209 1639

 

  1. Use your graphing calculator to to construct a frequency histogram of the data with 5 classes.  Is it reasonable to assume that the life span is normally distributed?
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  2. Find the mean and standard deviation of your sample to three significant figures.
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    «math xmlns=¨http://www.w3.org/1998/Math/MathML¨»«mi»§#963;«/mi»«mo»=«/mo»«/math» {#3}

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