the one that starts with (-2,-2)
Answer:
The variance of these investment returns is 74
Step-by-step explanation:
Given:
Series = 10, 30, 15, 5, 20
To Find:
variance of a series = ?
Solution:
The variance of the series = 
Now 
= 
= 36 + 196 +121 + 1+ 16
= 370
Now
= 74
Answer:
x = 7, y = 6
Step-by-step explanation:
solve for y for the first equation
2x + y = 20
-2x -2x , eliminate 2x
y = 20-2x
now that we have found y, substitute the y in for the second equation
-5y = -6x + 12
-5(20-2x) = -6x + 12, we just changed y into 20-2x. remember that we are multiplying all of 20 - 2x by -5
-100+10x = -6x + 12, we multiplied everything from the parathesis by -5
+100 + 100, eliminate -100
10x = -6x + 112
+6x +6x , eliminate 6x
16x = 112 , solve for x
x = 7
then y = 20 - 2x = 20 - 2*7 = 6
check:
2 * 7 + 6 = 20
20 = 20
-5 * 6 = -6 * 7 + 12
-30 = -42 + 12
-30 = -30
Answer:α
=
71
°
:
explain:
From trigonometry we have:
cos
α
=
7
21
7
=
21
cos
(
α
)
and:
α
=
a
r
c
cos
(
7
21
)
=
70.5
≈
71
∘
