Question 1

A researcher is comparing the reaction times of 10-year-olds who play video games and 10-year-olds who do not. Random samples from each group provided the results shown below.

 Reaction times of 10-year-olds 

 Players of Video Games Non-players of Video Games 

Sample size

15

10

Mean reaction time

(seconds)

0.50

0.52

Standard deviation of reaction times (seconds)

0.01

0.02

Assume that the reaction times for both populations are normally distributed with the same population standard deviation.

7 marksa.Construct a 98% confidence interval for the difference between the population means of reaction times.

Note: Express your answer to 5 decimal places of accuracy.

8 marksb.Using a 2.5% significance level, can the researcher conclude that the mean reaction time of players of video games is less than the mean reaction time of non-players of video games? Formulate and test the appropriate hypotheses. Use the critical value approach.