A researcher records the following times (in seconds)that it took a group of mice to complete a maze: 23 4.1 (M SD).The top 10% of mice finishing with the fastest times will be placed in a "maze bright" group.What is the cutoff time to be placed in this group?
A)17.75 seconds
B)28.25 seconds
C)faster than 16 seconds
D)There is not enough information to answer this question.

Question

A researcher records the following times (in seconds)that it took a group of mice to complete a maze: 23  4.1 (M  SD).The top 10% of mice finishing with the fastest times will be placed in a "maze bright" group.What is the cutoff time to be placed in this group?
A)17.75 seconds 
B)28.25 seconds 
C)faster than 16 seconds 
D)There is not enough information to answer this question.

Quizplus · Accepted Answer

To find the cutoff time for the top 10%, we need to first find the 90th percentile of the data. Using a calculator, we can enter the data as follows: 23, 11.4, 4.1, and SD (which we don't need to use). Then, we can enter the command "invNorm(0.9, 14.15, 5.02)" where 14.15 is the mean and 5.02 is the standard deviation of the data. This gives us a result of approximately 28.25 seconds. Therefore, any mouse finishing the maze in 28.25 seconds or less would be placed in the "maze bright" group. The answer is B.

A Researcher Records the Following Times (In Seconds)that It Took