Answer:
a = 3
b = 2
c = 0
d = -4
Step-by-step explanation:
Form 4 equations and solve simultaneously
28 = a(2)³ + b(2)² + c(2) + d
28 = 8a + 4b + 2c + d (1)
-5 = -a + b - c + d (2)
220 = 64a + 16b + 4c + d (3)
-20 = -8a + 4b - 2c + d (4)
(1) + (4)
28 = 8a + 4b + 2c + d
-20 = -8a + 4b - 2c + d
8 = 8b + 2d
d = 4 - 4b
Equation (2)
c = -a + b + d + 5
c = -a + b + 4 - 4b+ 5
c = -a - 3b + 9
28 = 8a + 4b + 2c + d (1)
28 = 8a + 4b + 2(-a - 3b + 9) + 4 - 4b
28 = 6a - 6b + 22
6a - 6b = 6
a - b = 1
a = b + 1
220 = 64a + 16b + 4c + d (3)
220 = 64(b + 1) + 16b + 4(-b - 1 - 3b + 9) + 4 - 4b
220 = 60b + 100
60b = 120
b = 2
a = 2 + 1
a = 3
c = -3 - 3(2) + 9
c = 0
d = 4 - 4(2)
d = -4
Answer:
a)
b) 
c) 
Step-by-step explanation:
Part a
The significance level given is 
and the degrees of freedom are given by:
Since we are conducting a right tailed test we need to find a critical value on the t distirbution who accumulates 0.1 of the area in the right and we got:
Part b
The significance level given is 
and the degrees of freedom are given by:
Since we are conducting a left tailed test we need to find a critical value on the t distirbution who accumulates 0.01 of the area in the left and we got:
Part c
The significance level given is 
and 
and the degrees of freedom are given by:
Since we are conducting a two tailed test we need to find a critical value on the t distirbution who accumulates 0.025 of the area on each tail and we got:
Standard deviation = √(n * p * q)
You are given n and p
q = 1 - p
q = 1 -0.2 = 0.8
Standard deviation = √(21 * 0.2 * 0.8)
=√3.36 = 1.83
The answer is A.
