The number of words typed per minute was measured for a sample of typists. The following display from a TI-84 Plus calculator presents a 95% confidence interval for the population mean typing speed.

a. Fill in the blanks: We are _____________ confident that the population mean number of words per minute is between _____________ and ___________________.

b. Assume the population is not normally distributed. Is the confidence interval still valid? Explain.

Transcribed Image Text:

ZInterval (56.019.60.881) x=58.45 n=65