Question

A study of peach trees showed that the average number of peaches per tree was 2000. The standard deviation of the population is 200. A scientist wishes to find the 99% confidence interval for the mean number of peaches per tree. How many trees does she need to sample to be accurate within 16 peaches per tree?

Answer 1

Solution :

Given that,

standard deviation =s =   =200

Margin of error = E = 16

At 99% confidence level the z is,

= 1 - 99%

= 1 - 0.99 = 0.01

/2 = 0.005

Z/2 = 2.58

sample size = n = [Z/2* / E] 2

n = ( 2.58*200 / 16 )2

n =1040

Sample size = n =1040