.
The test score of a math class with 800 students are distributed normally with a mean of 75 and a standard deviation of 7.
a) What percentage of a class has a test score between 68 and 82?
b) Approximately how many students have a test score between 61 and 89?
c) What is the probability that a student chosen at random has a test score between 54 and 75?
d) Approximately how many students have a test score greater than or equal to 96?
~~~~~~~~~~~~~~~~~~
(a) They want you find the area under the specified normal curve between given raw scores
For it, use you calculator P = normalcfd(68, 82, 75, 7)
or use online free of charge calculator https://onlinestatbook.com/2/calculators/normal_dist.html
The answer is 0.6827 (rounded).
(b) First find the probability as the area under the specified normal curve between the given raw scores
For it, use you calculator P = normalcfd(61, 89, 75, 7)
or use online free of charge calculator https://onlinestatbook.com/2/calculators/normal_dist.html
The probability (the area under the curve) is 0.9545 (rounded).
Therefore, the answer to question (b) is this product 0.9545*800.
Use your calculator and round appropriately.
Solved.
In the future, do not pack too many questions in one post.
