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Math Help - Probability Distributions???Grades and Proportion

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    Unhappy Probability Distributions???Grades and Proportion

    Hi, if someone could please help me, That would be great. The question is On the midterm exam, an instructor always gives a grade of B to students who score between 80 and 90. On one year the scores on the exam have appx a normal distribution with mean 83 and standard deviation 5. About what proportion of students get a B?........?????
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    Quote Originally Posted by Hunt67 View Post
    Hi, if someone could please help me, That would be great. The question is On the midterm exam, an instructor always gives a grade of B to students who score between 80 and 90. On one year the scores on the exam have appx a normal distribution with mean 83 and standard deviation 5. About what proportion of students get a B?........?????
    Pr(80 < X < 90) = Pr(-0.6 < Z < 1.4) = Pr(0 < Z < 0.6) + Pr(0 < Z < 1.4).

    Now use your standard normal distribution table to find the required probabilities.
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