Answer:
<h2>
$5.03</h2>
Step-by-step explanation:
Given data
Sample Mean (M): $48.77
Sample Size (n): 20
Standard Deviation (σ) : $17.58
Confidence Level: 80%
we know that z*-Values for 80% Confidence Levels is 1.28
the expression for margin of error is given bellow\
MOE= z*σ/√n
We can now substitute into the expression and solve for the MOE as
MOE= 1.28*17.58/√20
MOE= 22.502/4.47
MOE= 22.502/4.47
MOE= 5.03
The margin of error for a 80 % confidence interval is $5.03
Answer:
Sum of the first 15 terms = -405
Step-by-step explanation:
a + 3d = -15 (1)
a + 8d = -30 (2)
Where,
a = first term
d = common difference
n = number of terms
Subtract (1) from (1)
8d - 3d = -30 - (-15)
5d = -30 + 15
5d = -15
d = -15/5
= -3
d = -3
Substitute d = -3 into (1)
a + 3d = -15
a + 3(-3) = -15
a - 9 = -15
a = -15 + 9
a = -6
Sum of the first 15 terms
S = n/2[2a + (n − 1) × d]
= 15/2 {2×-6 + (15-1)-3}
= 7.5{-12 + (14)-3}
= 7.5{ -12 - 42}
= 7.5{-54}
= -405
Sum of the first 15 terms = -405
P = 2(L + W)
P = 258
L = 2W - 9
258 = 2(2W - 9 + W)
258 = 2(3W - 9)
258 = 6W - 18
258 + 18 = 6W
276 = 6W
276/6 = W
46 = W <=== here is the width
L = 2W - 9
L = 2(46) - 9
L = 92 - 9
L = 83 <== here is the length
