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.