Answer:
a) Margin of error = 166.311
b) sample size ≥ 62
Step-by-step explanation:
Given:
Average cost = $1599
Sample size = 50 persons
Standard deviation = $600
Confidence level is 95%
a) Margin of error = 
Now for confidence level of 95% z-value = 1.96
Thus,
Margin of error = 
or
Margin of error = 166.311
b) For Margin of error ≤ 150
≤ 150
or
≤ 150
or
≤ √n
or
√n ≥ 7.84
or
n ≥ 61.4656
Therefore,
sample size ≥ 62
Answer:
Step-by-step explanation:
A.
R(x)=px=x(-45 x+1800)=-45 x²+1800 x
B.
C(x)=7000+100 x
C.
P(x)=R(x)-C(x)=-45 x²+1800 x-(7000+100 x)
or P(x)=-45x²+1800 x-100 x-7000
or P(x)=-45 x²+1700 x-7000
I basically pick a couple random numbers for both variables and plug them in to see if they are true.
4- 7x = 23- 5
4 - 7x = 18
-4 = -4
-7x = 14
/-7 = /-7
X = -2
3x = -6