5. On another test, a sample of 50 students obtained a mean score of 14.3 with a standard deviation of 2.0. Unfortunately, it turned out that some of the test questions had been wrongly scored, and when the tests were re-scored, it was discovered that every student's score had been increased by a factor such that the variance of the scores was now 9.0. Given this, what is the new mean of the scores?
5. On another test, a sample of 50 students obtained a mean score of 14.3 with a standard deviation of 2.0. Unfortunately, it turned out that some of the test questions had been wrongly scored, and when the tests were re-scored, it was discovered that every student's score had been increased by a factor such that the variance of the scores was now 9.0. Given this, what is the new mean of the scores?
MATLAB: An Introduction with Applications
6th Edition
ISBN:9781119256830
Author:Amos Gilat
Publisher:Amos Gilat
Chapter1: Starting With Matlab
Section: Chapter Questions
Problem 1P
Related questions
Question
Answer question 5
Answer question 3d and 3e
Transcribed Image Text:3.
4.
The following are the test scores of a sample of 20 students:
16, 22, 26, 30, 32, 33, 34, 36, 36, 37, 38, 38, 39, 40, 41, 41, 43, 47, 51, 56
What is the median score?
What is the mean score?
CWhat is (are) the mode(s)?
Is there any reason to believe that the distribution of scores is skewed? Why or why
not?
e Use the computing formula (not the definitional formula) to find the variance and
standard deviation of the scores. Confirm your answers by keying the data into your
calculator and using it to compute the mean, standard deviation and variance for you.
Another sample, consisting of 15 students, obtained a mean score of 45.5, a median score
of 44, and a standard deviation of 4.2 on the same test given to the sample in question #3.
What is the grand mean (i.e., the mean of both sample's scores combined)?
Is there any way to compute the "grand median" of these data? If not, why not? If so,
what is its value?
On another test, a sample of 50 students obtained a mean score of 14.3 with a standard
deviation of 2.0. Unfortunately, it turned out that some of the test questions had been
wrongly scored, and when the tests were re-scored, it was discovered that every student's
score had been increased by a factor such that the variance of the scores was now 9.0.
Given this, what is the new mean of the scores?
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