Problem

A survey of 5 people was conducted to find out how many books they read in a month. The results were: 3, 4, 8, 1, and 6. Calculate the mean and standard deviation.

Solution

Step 1 :Step 1: Calculate the mean (average) by adding up the values and dividing by the number of values: \(\frac{3+4+8+1+6}{5} = \frac{22}{5} = 4.4\)

Step 2 :Step 2: Subtract the mean from each value to get the deviation from the mean: \(3-4.4=-1.4, 4-4.4=-0.4, 8-4.4=3.6, 1-4.4=-3.4, 6-4.4=1.6\)

Step 3 :Step 3: Square each deviation to get the squared deviations: \((-1.4)^2=1.96, (-0.4)^2=0.16, 3.6^2=12.96, (-3.4)^2=11.56, 1.6^2=2.56\)

Step 4 :Step 4: Calculate the mean of the squared deviations: \(\frac{1.96+0.16+12.96+11.56+2.56}{5} = \frac{29.2}{5} = 5.84\)

Step 5 :Step 5: The standard deviation is the square root of the mean of the squared deviations: \(\sqrt{5.84} = 2.42\)

From Solvely APP
Source: https://solvelyapp.com/problems/B9dJIYVzzs/

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