The box plot compares the number of events that Mrs. Cai’s and Mr. Roland’s classes won over the last 10 years on the school’s field day.

A number line goes from 0 to 10. Mrs. Cai's class's whiskers range from 0 to 8, and the box ranges from 2 to 4. A line divides the box at 3. Mr. Roland's class's whiskers range from 1 to 8, and the box ranges from 4 to 7. A line divides the box at 5.
Based on the data in the box plots, what is the best evidence to show which class has had greater success on field day over the last 10 years?

Mrs. Cai’s class was more successful because her interquartile range was less spread out.
Mrs. Cai’s class was more successful because she had the greater total spread.
Mr. Roland’s class was more successful because his class always won at least one event.
Mr. Roland’s class was more successful because his class’s lower quartile was the same as Mrs. Cai’s class’s upper quartile.

In this problem, we explore the effect on the standard deviation of multiplying each data value in a data set by the same constant. consider the data set 14, 6, 8, 15, 15. (a) use the defining formula, the computation formula, or a calculator to compute s. (round your answer to one decimal place.) s = 4.28 (b) multiply each data value by 3 to obtain the new data set 42, 18, 24, 45, 45. compute s. (round your answer to one decimal place.) s = 12.83 (c) compare the results of parts (a) and (b). in general, how does the standard deviation change if each data value is multiplied by a constant c? multiplying each data value by the same constant c results in the standard deviation remaining the same. multiplying each data value by the same constant c results in the standard deviation being |c| times as large. multiplying each data value by the same constant c results in the standard deviation increasing by c units. multiplying each data value by the same constant c results in the standard deviation being |c| times smaller. (d) you recorded the weekly distances you bicycled in miles and computed the standard deviation to be s = 3.8 miles. your friend wants to know the standard deviation in kilometers. do you need to redo all the calculations? yes no given 1 mile ≠1.6 kilometers, what is the standard deviation in kilometers? (enter your answer to two decimal places.)