Scores on an exam are normally distributed with a mean of 76 and a standard deviation of 10. In a group of 230 tests, how many students score above 96?
The score of 96 is 2 standard deviations above the mean score. Using the empirical rule for a normal distribution, the probability of a score above 96 is 0.0235.
Therefore the number of students scoring above 96 is given by:
\(230\times 0.0235=5\ students\)
Using the normal distribution, it is found that 5 students get scores that are above 96.
The z-score of a measure X of a normally distributed variable with mean \(\mu\) and standard deviation \(\sigma\) is given by:
\(Z = \frac{X - \mu}{\sigma}\)
In this problem, the mean and the standard deviation are given, respectively, by:
\(\mu = 76, \sigma = 10\).
The proportion of students who scored above 96 is one subtracted by the p-value of Z when X = 96, hence:
\(Z = \frac{X - \mu}{\sigma}\)
\(Z = \frac{96 - 76}{10}\)
Z = 2
Z = 2 has a p-value of 0.9772.
1 - 0.9772 = 0.0228
Out of 230 students:
0.0228 x 230 = 5 students.
More can be learned about the normal distribution at https://brainly.com/question/24663213
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