Answer:
(a) Margin of error ( E) = $2,000 , n = 54
(b) Margin of error ( E) = $1,000 , n = 216
(c) Margin of error ( E) = $500 , n= 864
Step-by-step explanation:
Given -
Standard deviation
= $7,500
= 1 - confidence interval = 1 - .95 = .05
=
= 1.96
let sample size is n
(a) Margin of error ( E) = $2,000
Margin of error ( E) = 
E = 
Squaring both side


n = 54.0225
n = 54 ( approximately)
(b) Margin of error ( E) = $1,000
E = 
1000 = 
Squaring both side


n = 216
(c) Margin of error ( E) = $500
E = 
500 = 
Squaring both side


n = 864
Answer:
A system has infinitely many solutions when it is consistent and the number of variables is more than the number of nonzero rows in the rref of the matrix. For example if the rref is ��has solution set (4-3z, 5+2z, z) where z can be any real number.
We are to find the Probability the someone buys a book that is paperback and fiction.
Let P(F) represents the event that the book is fiction and P(P) represents the event that the book is paperback. We are to find P(F∩P)
P(F∩P) = P(F) x P(P)
From the tree diagram we can see that:
P(F) = 0.45
P(P) = 0.65
Using the values, we get:
P(F∩P) = 0.45 x 0.65 = 0.2925
So, the Probability the someone buys a book that is paperback and fiction is 0.2925.
So, option B gives the correct answer