Question

In a statistics class, 8 students took their pulses before and after being frightened. The frightening event was having the teacher scream and run from one side of the room to the other. The pulse rates (beats per minute) of the students before and after the scream were obtained separately and are shown in the table. Treat this as though it were a random sample of community college students. Test the hypothesis that the mean of college students' pulse rates is higher after a fright using a significance level of 0.05. Do the 5-step hypothesis test and submit an image of your work.

Participant #	1	2	3	4	5	6	7	8
Pulse Before	93	86	70	73	83	92	83	62
Pulse After	102	87	73	74	87	98	83	71

Answer 1

Solution:

Here, we have to use paired t test.

H₀: µ_d = 0 versus H_a: µ_d < 0

We take difference as before minus after.

Test statistic for paired t test is given as below:

t = (Dbar - µ_d)/[S_d/sqrt(n)]

From given data, we have

Dbar = -4.1250

S_d = 3.5632

n = 8

df = n – 1 = 7

α = 0.05

t = (-4.1250 – 0) / [3.5632/sqrt(8)]

t = -3.2744

P-value = 0.0068

(by using t-table)

P-value < α = 0.05

So, we reject the null hypothesis

There is sufficient evidence to conclude that the mean of college students' pulse rates is higher after a fright.