In: Statistics and Probability
Locus of Control has μ = 106 and σ =12. Test whether ARC students (n = 36, M = 109) differ on Locus of Control. α = .05.
1. σM =
Solution:
Given in the question
Locus of Control has
Mean()
= 106
Standard deviation()
= 12
We need to test wheter ARC Students differs on Locus of control so
null and alternative hypothesis can be written as
Null hypothesis H0:
= 106
Alternate hypothesis Ha:
106
Sample size (n) = 36
Sample mean (Xbar) = 109
M =
/sqrt(n) = 12/sqrt(36) = 2
Here we will use Standard normal table as Population standard
deviation is known and sample size is large enough so test stat
value can be calculated as
Z test stat = (Xbar -
)//sqrt(n)
= (109-106)/12/sqrt(36) = 1.5
at alpha = 0.05, and this is two tailed test so from Z table we
found Zcritical value = +/-1.96
Decision Rule: Reject H0, if Test stat value is less than -1.96 or
test stat value is greater than 1.96, else do not reject the null
hypothesis.
Here we can see that test stat value is between 1.96 and -1.96. So
we are failed to reject the null hypothesis. And we dont have
significant evidence to support the claim that ARC Students differs
on Locus of control.