Question
$1.00 Probability Urgent & Simple: Assume that the mean SAT score in Mathematics for 11th graders across the nation is 500
- From Mathematics: General-Mathematics , Mathematics: Probability
- Closed, but you can still post tutorials
- Due on Apr. 12, 2012
- Asked on Apr 10, 2012 at 2:08:08PM
Q:
Q. Assume that the mean SAT score in Mathematics for 11th graders across the nation is 500, and that the standard deviation is 100 points. Find the probability that the mean SAT score for a randomly selected group of 150 11thgraders is between 480 and 520.
Here is my Answer so far..
μ = 500, σ = 100, n = 150
z = (x-bar - μ)/(σ/√n)
For x-bar = 480, z = (480 - 500)/(100/√150) = -2.4494
For x-bar = 520, z = (520 - 500)/(100/√150) = 2.4494
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P(480 < x-bar < 520) = P(-2.4494 < z < 2.4494) =
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Please complete the Last step.
Thanks
Note: ignore the above 2 html lines..donno how it came..