
Concept explainers
For Problem 19.1, using Equations (19.1) and (19.6), calculate the mean and standard deviation of the class scores.

Calculate the mean and standard deviation of the class scores.
Answer to Problem 3P
The mean and standard deviation of class scores are 73.2 and 12.5 respectively.
Explanation of Solution
Given data:
The required data are given below with reference to the problem 19.1 in the textbook.
Number of students,
Students test scores are 57, 94, 81, 77, 66, 97, 62, 86, 75, 87, 91, 78, 61, 82, 74, 72, 70, 88, 66, 75, 55, 66, 58, 73, 79, 51, 63, 77, 52, 84.
Formula used:
From equation 19.1 in the textbook, the formula to find mean for any sample is,
Here,
From equation 19.6 in the textbook, the formula to find standard deviation is,
Calculation:
Substitute all the value of student scores for
Find the terms
Substitute all the value
Therefore, the mean and standard deviation of class scores are 73.2 and 12.5 respectively.
Conclusion:
Thus, the mean and standard deviation of class scores are 73.2 and 12.5 respectively.
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Chapter 19 Solutions
ENGINEERING FUNDAMENTALS
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