Let's look at the exam result of
E370 first Saturday exam. It's taken from all sections.
Assume that the scores follow a normal distribution with mean 70.55 and standard deviation 14.76.
Please answer question 1 to 5.
1. Kevin's score for the test is 90. Calulate the relative magnitude of the score in terms of percentiles.
Percentitle=
0.91
2. What is the proportion of students whose scores are from 70 to 92?
Proportion=
#NAME?
3. Calculate z-scores for 70 and 92. Then get the probability using the standard normal distribution. Do you
z1 = (70-70.55)/14.76 =
-0.04
z2 = (92-70.55)/14.76 =
1.45
Then,
Proportion=
#NAME?
4. 40% of all students score less than John. Calculate John's score.
John's Score =
66.81
5. What is the z-score associated with John's score?
Use z-score and the standard normal distribution to get the probability that one will score more than Joh
z-score= (66.8106-70.55)/14.76 =
-0.25
Prob(score >= John's) = Err:509
Now suppose that somehow we couldn't get the standard devaition of the scores of the whole E370
A sample of Guang's section which has 82 E370 students is taken to get the standard deviation whi
Please answer question 6 to 9.
6. What are the t-scores of 70 and 92?

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