Question 421339
Students grades were normally distributed with a mean of 73 and a standard deviation of 11.
a. 7.93 percent of the students received grades of A. what is the minimum score needed to receive a grade of A?
Find the z-value with a right tail of 7.93%
invNorm(1-0.0793) = 1.4098
Find the corresponding x-value using x = zs+u
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x = 1.4098*11 + 73 = 88.51
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b. Students who made 57.93 or lower on the exam failed the course. What percent of students failed the course?
Same process as with part "a":
Find the z-value of 57.93
Find the corresponding x-value.
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c. If 69.5 percent of the syudents received grades of C or better, what is the minimum score of those who received a C?
Same process as with part "a" and part "b".
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Cheers,
stan H.