Question

A study of lemon trees found that the average number of lemons per tree was 725. The
standard deviation of the population is 70 lemons per tree. A scientist wishes to find the
80% confidence interval for the mean number of lemons per tree. How many trees does
she need to sample to obtain an average accurate to within 16 lemons per tree?

Answer 1

if i recall correctly, this might help
\[n=(\frac{z\sigma }{E})^2\]

Answer 2

id have to read up on it to be sure :)

Answer 3

This question has been answered on here before acorrding to google but I can't find it

Answer 4

Well remember the standard deviation of a sample population is
\[
\sigma \over n^2
\]

Use a z-score chart to find the 80% confidence interval

Answer 5

\[CI=\bar x\pm \frac{z\sigma}{\sqrt{n}}\]
\[\sqrt{n}=\pm \frac{z\sigma}{CI-\bar x}\]
\[n=(\frac{z\sigma}{CI-\bar x})^2\]
maybe

Answer 6

z = 1.282

CI-mean = E

\[n=\frac{1.282(70)}{16}=31.45\]
so id say 32 if I did it right