Statistics and Probability Answers

The overhead reach distances of adult females are normally distributed with a mean of 205.5 cm and a standard deviation of 8.6 cm.

a. Find the probability that an individual distance is greater than 218.90 cm.

b. Find the probability that the mean for 25 randomly selected distances is greater than 203.70 cm.

c. Why can the normal distribution be used in part​ (b), even though the sample size does not exceed​ 30?

Two methods of teaching statistics are being tried by a professor. A class of 40 students is taught by method A and a class of 36 is taught by method B. the two classes are given the same final examination. The scores are: Using the .01 significance level, can we conclude that the average final examination scores produced by the two methods are different if the population standard deviation is 5?

Two methods of teaching statistics are being tried by a professor. A class of 40 students is taught by method A and a class of 36 is taught by method B. the two classes are given the same final examination. The scores are: Using the .01 significance level, can we conclude that the average final examination scores produced by the two methods are different if the population standard deviation is 5?