Help anyone?? need to get this done

What is the standard deviation of the following data set rounded to the nearest tenth? 3, 17, 18, 15, 12, 21, 9

Aswimming pool had 2.5 million liters of water in it. some water evaporated, and then the pool only had 22 million liters of water in it. what percent of the water evaporated?

Select the correct answer from each drop-down menu. the table shows the annual sales revenue for different types of automobiles from three automobile manufacturers. sales revenue (millions of dollars) suv sedan truck marginal total b & b motors 22 15 9 46 pluto cars 25 27 10 62 panther motors 26 34 12 72 marginal total 73 76 31 180 the company with the highest percentage of sales revenue from sedans is . of the annual sales revenue from suvs, the relative frequency of pluto cars is .