Question

A sample of college students was asked how much they spent monthly on cell phone plans. approximate the standard deviation for the
cost.
monthly cell phone plan cost (5)
number of students
10.00-19.99
7
20.00-29.99
20
30.00-39.99
28
40.00-49.99
12
50.00-59.99
7

Answer 1

The standard deviation for the cost of mobile cell phones is 10.925.

Given

Mobile cell phone cost                    Number of students

10-19.99                                                   7

20-29.99                                                 20

30-39.99                                                 28

40-49.99                                                  12

50-59.99                                                   7

We have to calculate the standard deviation of the given data.

Standard deviation is a measure which measures the variation in te values of data sets.

We know that the formula of calculating standard deviation is as under:

Standard deviation=$\sqrt{sum of f(x- mean)^{2} }$/$\sqrt{sum of f-1}$

Mean=33.91392   (calculated in figure)

∑f$(x-mean)^{2}$=8713.514      (calculated in image)

∑f-1=74-1=73

We have to now just put the values and find the value of standard deviation.

Standard deviation=$\sqrt{8713.514/73}$

=$\sqrt{119.36}$

=10.925

Hence the standard deviation of mobile cost is 10.925.

Learn more about standard deviation at brainly.com/question/475676

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