Question

Grace is looking at a report of her monthly cell-phone usage for the last year to determine if she needs to upgrade her plan. The list represents the approximate number of megabytes of data Grace used each month.


700, 735, 680, 890, 755, 740, 670, 785, 805, 1050, 820, 750
What is the standard deviation of the data? Round to the nearest whole number.

Answer 1

Answer:

s ≈ 105

Step-by-step explanation:

Given:

• The data set: 700, 735, 680, 890, 755, 740, 670, 785, 805, 1050, 820, 750

To find:

• The standard deviation of the data

Steps:

To find the standard deviation, first write the computational formula for the standard deviation of the sample.

${s}= \sqrt{\frac{{\sum}{x^2} - \frac{({\sum}{x})^2}{n}}{n - 1}}$

Take the square root of the answer found in step 7 above. This number is the standard deviation of the sample. It is symbolized by $s$ . Here, we round the standard deviation to the nearest whole number.

${s} = \sqrt{10987.878787879} = 104.8231$

Rounding to the nearest whole number:

s ≈ 105