Answer:
a) 
b) The should sample at least 293 small claims.
Step-by-step explanation:
We have that to find our
level, that is the subtraction of 1 by the confidence interval divided by 2. So:

Now, we have to find z in the Ztable as such z has a pvalue of
.
So it is z with a pvalue of
, so
, which means that the answer of question a is z = 1.645.
Now, find the margin of error M as such

In which
is the standard deviation of the population and n is the size of the sample.
(b) If the group wants their estimate to have a maximum error of $12, how many small claims should they sample?
They should sample at least n small claims, in which n is found when
. So







The should sample at least 293 small claims.
Given:
Total amount invested = $9,000
interest rates = 4% and 6%
Let x be the part of 9,000.
Note that annual return on each investment is the same.
0.04x = 0.06(9,000 - x)
0.04x = 540 - 0.06x
0.04x + 0.06x = 540
0.10x = 540
x = 540/0.10
x = 5,400
0.04x = 0.06(9,000 - x)
0.04(5,400) = 0.06(9,000 - 5,400)
216 = 0.06(3,600)
216 = 216
total interest for the year : 216 + 216 = 432
Interest = pricipal * interest rate * term
432 = 9,000 * interest rate * 1 yr
432/9,000 = interest rate
0.048 = interest rate
Interest rate would be 4.8% to get the same interest from the whole 9,000.
Answer:
-4
Step-by-step explanation:
y = 3(x +1) -7
y = 3x -4
-4
Answer:
D
Step-by-step explanation:
1/2 ( 2x - 6) = -6
1/2 = 0.5
0.5(2x-6) = -6
1x-3=-6
1x=-6+3
x=-3/1
x=-3