Answer:
O <u>4th option</u> : <u>(-4, -2)</u>
Step-by-step explanation:
⇒ 9x - 9y = -18
⇒ -<u>6x + 9y = 6</u>
- 9(-4) - 9y = -18
- -36 - 9y = -18
- -9y = 18
- y = -2
⇒ (x , y)
⇒ <u>(-4, -2)</u>
We have been given that the standard deviation of a group of 20 scores is 15 and we are asked to find variance.
Since we know variance is square of standard deviation. In order to find out the variance of the given data we have to take the square of 15.

Therefore, our variance is 225.
The surface area would be 166.
1.5 cups per day...7 days per week....1.5 * 7 = 10.5 cups per week
16 cups = 1 gallon
16/1 = 10.5/x....16 cups to 1 gal = 10.5 cups to x gal
cross multiply
(16)(x) = (1)(10.5)
16x = 10.5
x = 10.5/16
x = 0.65625 rounds to 0.66 gallons per week