Hello from MrBillDoesMath!
Answer:
The first choice ( -12, 20)
Discussion:
Using matrix multiplication we find the equations:
1x + 1y = 8 (A)
2x + 3y = 36 (B)
Next, compute
2(A) - B =>
(2x + 2y) - (2x + 3y) = 2*8 - 36 =>
(2x - 2x) + ( 2y-3y) = 16 - 36 =>
-y = -20 =>
y = 20
Substituting this y value in (A) gives
x + 20 = 8 =>
x = 8 - 20 =>
x = -12
The answer is the first choice ( -12, 20)
Thank you,
MrB
i believe the formula you need is; SA= n(3/10 ib) + 9b
The mean distance for a group is the sum of individual numbers over the number of data. The mean distance of Group A is (1+1.5+3+3.2+2.8+1.5+1.8+2.5+2.2)/9=2.17 The mean distance of Group B is (<span>2+2.5+3.2+3+1.8+2.4+3+1.5+1.8)/9=2.36. Therefore, the mean is greater for group B than group A, but not doubling.</span>
