The lengths of 45 French fries, randomly selected from a huge shipment, were measured and a mean length of 8.4 cm with standard deviation of 3.1 cm was found.
a. Construct a 95% confidence interval for the population mean length of a French fry.
b. Calculate the number of French fries that would have to be sampled and measured to be 98% sure of being within 0.4 cm of the true mean.
The confidence interval has been constructed and the sample size determined.