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.
Answer:
Infinite.
Step-by-step explanation:

Expand:

Add 6 to both sides:


Subtract 3x from both sides:


No matter what x is, it doesn't affect the answer. Thus, the equation is true for all values of x.
Answer:
The first one is a the second one is b
Step-by-step explanation:
B
For example if it has been 2 months (l=1.25 times 2) the length would be 1.5 cm
Answer:
140
Step-by-step explanation:
20+4(s)=
20+4(30)=
20+ 120=
140