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Standard deviation

Please use MINITAB to solve or explain how I can use MINITAB to solve.

7. Assume that the midterm's scores X are normally distributed. Let X have a mean of 72 and a standard deviation of 12. Then answer the following three questions:

a. What is the probability of obtaining a score at least 90?
b. What is the probability of obtaining a score at most 75?
c. What is the probability of obtaining a score between 60 and 79?

Solution Preview

Cumulative Distribution Function
<br>
<br>Normal with mean = 72.0000 and standard deviation = 12.0000
<br>
<br> x P( X <= x )
<br> 90.0000 0.9332
<br>
<br>SO Prob of at least 90 = 1 - .9332
<br>
<br>Cumulative Distribution ...

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