Managers are eager to test a new irrigation system and did so during this year's production cycle of pineapples.

**5. How large a sample would you need to take to estimate the mean weight of the pineapples produced within one ounce at a 95% confidence level?**

(the sigma is 2.5 ounces in the original problem)

So I did this:

x(bar) +/- z*(sigma/sqrt n)

z*=95%= 1.96

sigma/sqrt n = 1 oz

2.5/sqrt n =1

2.5/sqrt n sqr=1 sqr

2.5 * 2.5/n= 1*2.5=2.5

1.96*2.5=n=4.9

This is not right and I dont know where I went wrong...

**An SRS of 50 pineapples taken from this year's crop had amean weight of 31.6.**

6. Use a 95% confidence interval to dertermine whether this sample provides evidence of a change in the mean weight of pineapples produced. Explain your reasoning.

6. Use a 95% confidence interval to dertermine whether this sample provides evidence of a change in the mean weight of pineapples produced. Explain your reasoning.

So:

n=50

z*=1.96

mew= 31.6

so do I use the mew +/- z*(sigma/sqrt 50)?

If so, this would be, 31.6 +/- 1.96(sigma/sqrt 50)?

I am so lost at this point....