Answer:
x=-5, y=-5. (-5, -5).
Step-by-step explanation:
-x-5y=30
10x+5y=-75
------------------
9x=-45
x=-45/9
x=-5
-(-5)-5y=30
5-5y=30
5y=5-30
5y=-25
y=-25/5
y=-5
Answer:
The mean and standard deviation of Y are, 94 and 0.28 respectively.
Step-by-step explanation:
Let the random variable , 'Test grades on the last statistics exam' be X.
Then according to the question,
E(X) = 78 ------------(1)
and
= 0.14------------(2)
Now, according to the question,
Y = 2(X - 31)
⇒E(Y) = 2(E(X) - 31)
=
= 94 ----------------(4)
and
V(Y) = 4V(X)
⇒
⇒ = 0.28
So, the mean and standard deviation of Y are, 94 and 0.28 respectively.
Answer:
x = 10 ft
Step-by-step explanation:
By Pythogorus theorem,
x^2 = 8^2 + 6^2
x^2 = 64 + 36
x^2 = 100
x = sqrt(100)
x = 10 ft
$60 so u double 30 as it is 50 percent and 50 is half a hundred percent so it is $60