In a
sample of 1000 cases, the means of a
certain test is 14 and standard deviation
is 2.5. Assuming the distribution to be
normal sind.
al how many students score between 12 and 15?
b) how many score above 18?
C) how many score below 8?
d) how many score 16?
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Secondary School
Math
13 points
In a sample of 1000 cases, the mean of a certain test is 14 and s.d. is 2.5. assuming the distribution to be normal, find(a) how many students score between 12 and 15?(b) how many score above 18?(c) how many score below 8?(d) how many score 16?
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by Kumarvivek322 13.03.2018
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Solutions:n = 1000, mean = 14 and standard deviation = 2.5Should say +0.4b. How many score above 18?1-.9452=.054799 * 1000 = 54.80c.
How many score below 18?.9452 = 945.20d.
What is probability that the test score is between 15 and 18?.9452-.6554=0.2898e.
The top 20% of the students will score how many points above the mean?=norminv(.80,14,2.5) = 16.10 or moreP-10
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