The average weight of a medium size egg is found to be 3.2 oz, with a standard deviation of 0.13 oz. What is the heaviest egg (to 2 decimal places) that we are 95% confident is still medium size?

We are 95% confident that the average weight of the heaviest egg that is still medium size is 3.52 oz

Step-by-step explanation:

Mean = 3.2 oz, sd = 0.13 oz

Assuming there are 3 heavy eggs, n = 3, degree of freedom = n-1 = 3-1 = 2, t-value corresponding to 2 degrees of freedom and 95% confidence level is 4.303

Error margin = t*sd/√n = 4.303*0.13/√3 = 0.32 oz

Upper limit (heaviest egg that is still medium size) = mean + error margin = 3.2 + 0.32 = 3.52 oz