Probability and statistics ques

[sstudent]

QUES: the yield of a chemical process is bieng studied. the past 5 days of plant operation have resulted in :91.6, 88.75, 90.08, 89.95, 91.3. Find a 95% two-sided confiendce interval. Thanks folks

 

[rootX]

I don't know the answer.

But, you need to show some of your effort before anyone else going to help you.

 

[sstudent]

i tried using the eqautaion "Confiendnce interval on the mean, varaiance known" but i am not sure how to get the variance. thanks

 

[konthelion]

Let $$\bar{x}$$ be the sample mean, what is $$\bar{x}$$?
What is n, the sample size?
What is s, the sample standard deviation?
What distribution should you use(based on n)? Then find the 95% confidence interval.