Sandwiches sold at a local grocery store claim to have 6 grams of fat per sandwich.Ten sandwiches are brought with results of a mean of 5.93g of fat and a standard deviation of 0.13g.If fat content is normally distributed,how large a sample of sandwiches would we need to be 95% confident that the sample mean is within 0.03g of the population mean?
A)97
B)96
C)73
D)62
E)10

Question

Quizplus · Accepted Answer

To find the sample size needed for a specific margin of error, we use the formula for the sample size of a mean: n = (Z * σ / E)^2. Here, Z is the Z-score for 95% confidence (approximately 1.96), σ is the standard deviation (0.13), and E is the margin of error (0.03). Plugging in these values gives n ≈ 97.

Sandwiches Sold at a Local Grocery Store Claim to Have