Question

A random sample of 15 students reporting anxiety at the student health

center were given written instructions for breathing exercises that they might

employ when a situation provoked anxious feelings. Another 13 received a

series of talk/ counselling sessions. After 6 weeks, all of the students were

administered the State-Trait Anxiety Inventory (STAI) which measures current

anxiety and a propensity for anxiety. The average score for the students with

the breathing instruction was 36 with a standard deviation of 8. The average for

the students receiving counseling was 32 with a standard deviation of 6 (higher

scores=higher anxiety). Is counselling better than the breathing exercises in

controlling anxiety among college students? Use alpha=.05 and assume that

STAI scores are normally distributed and have equal variances in the

populations.

Answer 1

Controlling anxiety is getting low STAI scores. Therefore if we are testing whether counselling is better than the breathing exercises in controlling anxiety among college students that mean counselling should have low scores than breathing.

Since we do not have the population SD we are going to use t-dist also since we are checking if one is greater than the other that means it is a directional test.

	Counselling (1)	Breathing (2)
Mean	32	36
SD	6	8
Var	36	64
n	13	15

t-test for diff

: Counselling and breathing exercises are same in controlling anxiety among college students ( )

: Counselling is better than breathing exercises in controlling anxiety among college students ( )

This is one-sided right sided t-test for difference in population means.

Pooled variance =

= 51.077

Test Stat =

=

= -1.477

p-value = P ( > |T.S.| )

=

= 0.0758   ..............using t-dist tables with x = 1.477 and df = 26.

Level of significance

Since p-value > 0.05

We do not reject the null hypothesis at 0.05 level of significance. We conclude that counselling is significantly not better than the breathing exercises in controlling anxiety among college students