Question

A high school wanted to teach students about the effects of driving while under the influence. A police officer allowed students to wear special goggles that simulated the effects of driving while impaired. A random sample of eight students was selected. The reaction time it took for each student to stop from a speed of 55 mph was recorded while the student was not wearing the goggles (unimpaired) and then again while wearing the goggles (impaired). Round answers to two decimal places.

Participant

Unimpaired

Impaired

Difference

1	4.36	5.73	1.37
2	5.01	4.57	-0.44
3	4.14	5.54	1.4
4	4.62	5.53	0.91
5	4.56	5.23	0.67
6	4.17	5.78	1.61
7	4.54	5.1	0.56
8	4.7	5.47	0.77
Mean	4.51	5.37	0.86
SD	0.29	0.40	0.65

What is the value of the test statistic?

What is the critical value?

What decision do you make about the null? Type “reject” or “fail to reject” for your answer.

What is Cohen’s d?

Answer 1

Here we have 8 paired observations. we have to test whether there is effect special goggle, testing this hypothesis we use paired t test

the test statistic is

therefore

t=3.74

Statistic t has student t distribution with (n-1)=7 degrees of freedom

critical value of t is

here we observed that calculated t >tabulated t (critical t), hence we reject null hypothesis that there is no any impact of specially designed goggle.

that is specially designed goggle is good for driving