Use the tally chart to answer the question.
2 answers:
You might be interested in
Answer:
1,082
Step-by-step explanation:
The sample size n in Simple Random Sampling is given by
where
z = 1.645 is the critical value for a 90% confidence level (*)
s = 2 is the estimated population standard deviation
e = 0.1 mm points is the margin of error
so
rounded up to the nearest integer.
So the manufacturer should test 1,083 parts.
---------------------------------------------------------------------------------------
(*)This is a point z such that the area under the Normal curve N(0,1) outside the interval [-z, z] equals 10% = 0.1
It can be obtained in Excel with
NORMINV(1-0.05,0,1)
and in OpenOffice Calc with
NORMINV(1-0.05;0;1)