Question

The mean number of words per minute (WPM) typed by a speed typist is 136136 with a standard deviation of 1111 WPM.

What is the probability that the sample mean would differ from the population mean by greater than 11 WPM if 7676 speed typists are randomly selected? Round your answer to four decimal places.

PLEASE EXPLAIN IN CALCULATOR SPECIFALLY TI 83 PLUS

Answer 1

From the given information, n= 7676, mean 4 =136136 WPM and standard deviation o=1111 WPM. The probability that the sample mean would differ from the population mean by greater than 11 WPM is P(1-4>11) =P 1 - Hey 11 T, 1-4g = = P(Z >0.87) = 1-P(Z <0.87) 11 :P 11111 17676 = 1-0.8078= 0.1922. From the given information, n= - 76,mean 4 =136 WPM and standard deviation o =11 WPM. The probability that the sample mean would differ from the population mean by greater than 1 WPM is 1 - Le 1 P[E=#=)=P T, i-H 1 = P 11/ 75 = 1-0.7852 = 0.2148. wytro) = P(Z >0.79) = 1-P(Z <0.79)