Answer: 482
Step-by-step explanation:
Formula to find the sample size is given by :-
(1)
, where z* = critical z-value (two tailed).
= Population standard deviation and E = Margin of error.
As per given , we have
Margin of error : E= 3
Confidence level = 90%
Significance level =
Using z-table , the critical value for 90% confidence=
Required minimum sample size = [Substitute the values in formula (1)]
[ Round to the next integer]
Hence, the number of observations required is closest to 482.
The answer for this problem is -8x+2