Math

QuestionFind the range, variance, and standard deviation for the data set: 23, 32, 31, 45, 25, 33, 44, 47, 37, 32, 37, 48, 47, 50, 22, 40, 30, 28, 22, 39. Range is 28. Use sample formulas.

Studdy Solution

STEP 1

Assumptions1. The data represents samples, not a population. . We are asked to find the range, variance, and standard deviation.
3. The given data is2332314525334447373237484750224030282239\begin{array}{llllllllll} 23 &32 &31 &45 &25 &33 &44 &47 &37 &32 \\ 37 &48 &47 &50 &22 &40 &30 &28 &22 &39\end{array}

STEP 2

First, let's find the range of the data. The range is the difference between the highest and lowest values in the dataset.
Range=MaximumvalueMinimumvalueRange = Maximum\, value - Minimum\, value

STEP 3

Identify the maximum and minimum values from the given dataset.
Maximumvalue=50Maximum\, value =50Minimumvalue=22Minimum\, value =22

STEP 4

Substitute the maximum and minimum values into the range formula.
Range=5022Range =50 -22

STEP 5

Calculate the range.
Range=5022=28Range =50 -22 =28

STEP 6

Now, let's calculate the variance. The variance is a measure of how much the values in the dataset vary from the mean.The formula for the variance of a sample iss2=(xixˉ)2n1s^2 = \frac{\sum (x_i - \bar{x})^2}{n-1}Where- xix_i are the sample observations- xˉ\bar{x} is the sample mean- nn is the number of observations

STEP 7

First, calculate the mean of the dataset. The mean is the sum of all the values divided by the number of values.
xˉ=xin\bar{x} = \frac{\sum x_i}{n}

STEP 8

Calculate the sum of the dataset and the number of observations.
xi=23+32+31+45+25+33+44+47+37+32+37+48+47+50+22+40+30+28+22+39=732\sum x_i =23 +32 +31 +45 +25 +33 +44 +47 +37 +32 +37 +48 +47 +50 +22 +40 +30 +28 +22 +39 =732n=20n =20

STEP 9

Substitute the sum and the number of observations into the mean formula.
xˉ=73220\bar{x} = \frac{732}{20}

STEP 10

Calculate the mean.
xˉ=73220=36.6\bar{x} = \frac{732}{20} =36.6

STEP 11

Now, substitute the mean, the observations, and the number of observations into the variance formula.
s^ = \frac{(23-36.6)^ + (32-36.6)^ + \ldots + (22-36.6)^ + (39-36.6)^}{20-}

STEP 12

Calculate the variance.

STEP 13

The standard deviation is the square root of the variance.
s=s2s = \sqrt{s^2}

STEP 14

Substitute the variance into the standard deviation formula.

STEP 15

Calculate the standard deviation.

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