Answer:
x - 11
Step-by-step explanation:
Let f(x) = -5x - 4 and g(x) = 6x - 7.
f(x) + g(x)
I like to line them up vertically
-5x - 4
6x - 7
--------------
x-11
For this problem, the confidence interval is the one we are looking
for. Since the confidence level is not given, we assume that it is 95%.
The formula for the confidence interval is: mean ± t (α/2)(n-1) * s √1 + 1/n
Where:
<span>
</span>
α= 5%
α/2
= 2.5%
t
0.025, 19 = 2.093 (check t table)
n
= 20
df
= n – 1 = 20 – 1 = 19
So plugging in our values:
8.41 ± 2.093 * 0.77 √ 1 + 1/20
= 8.41 ± 2.093 * 0.77 (1.0247)
= 8.41 ± 2.093 * 0.789019
= 8.41 ± 1.65141676
<span>= 6.7586 < x < 10.0614</span>
Answer:
700
Step-by-step explanation:
2x + 2y = 6 . . . . . (1)
x + 3y = -1 . . . . . (2)
(1) x 3 => 6x + 6y = 18 . . . . . (3)
(2) x 2 => 2x + 6y = -2 . . . . . (4)
(3) - (4) => 4x = 20
x = 20/4 = 5
