Big Ideas Math Algebra 2, 2014
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Big Ideas Math Algebra 2, 2014 View details
Maintaining Mathematical Proficiency
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Exercise 5 Page 593

The standard deviation is the average amount by which each individual value deviates or differs from the mean.

About 7.09

Practice makes perfect

We want to find the standard deviation of the given data set. The first thing that should be done is rearranging the numbers from least to greatest. 21, 26, 28, 29, 32, 44 Let's now proceed to finding the mean that we need to calculate the standard deviation.

Mean

The mean of a data set is calculated by finding the sum of all values in the set and then dividing by the number of values in the set. In this case, there are 6 values in the set.
Mean=Sum of values/Number of values
Mean=21+26+28+29+32+44/6
Simplify right-hand side
Mean=180/6
Mean=30

Standard Deviation

The standard deviation of a set of data is the average amount by which each individual value deviates or differs from the mean. Standard Deviation sqrt((x_1-μ )^2+(x_2-μ )^2+... +(x_n-μ )^2/n) In the above formula, x_1, ... ,x_n are the values of the set of data, μ is the mean, and n is the number of values. For this exercise, the mean is 30 and there are 6 values in the data set. Let's use the value of the mean, 30, and apply the formula to each value in the set.

x_n x_n-μ (x_n-μ)^2
30 30-21=9 9^2=81
30 30-26=4 4^2=16
30 30-28=2 2^2=4
30 30-29=1 1^2=2
30 30-32=-2 (-2)^2=4
30 30-44=- 14 (- 14)^2=196
Sum of Values ≈ 303

Finally, we need to divide by 6 and then calculate the square root. Standard Deviation: sqrt(303/6)≈ 7.09 The standard deviation is about 7.09, so the typical value in the data set differs from the mean by about 7.09 units.