A psychology department secretary notices that the average number of student com

Question

A psychology department secretary notices that the average number of student complaints the department receives per week is 1.4 (mu = 1.4). He notices that the department has made some poor policy changes recently and wants to see if the number of complaints that the department receives has increased. He records the following number of complaints that came in per week for 8 weeks: 2, 4, 3, 5, 4, 1, 1, and 4. a) Test the hypothesis that the number of complaints has increased using a .05 level of significance. State the value for the test statistic and the decision to retain or reject the null hypothesis. b) Compute the effect size using estimated Cohen's d.

**I specifically need help calculating the standard deviation! I cannot get the right number.

Explanation / Answer

Given that,
population mean(u)=1.4
sample mean, x =3
standard deviation, s =1.5119
number (n)=8
null, Ho: =1.4
alternate, H1: >1.4
level of significance, = 0.05
from standard normal table,right tailed t /2 =1.895
since our test is right-tailed
reject Ho, if to > 1.895
we use test statistic (t) = x-u/(s.d/sqrt(n))
to =3-1.4/(1.5119/sqrt(8))
to =2.993
| to | =2.993
critical value
the value of |t | with n-1 = 7 d.f is 1.895
we got |to| =2.993 & | t | =1.895
make decision
hence value of | to | > | t | and here we reject Ho
p-value :right tail - Ha : ( p > 2.9932 ) = 0.01007
hence value of p0.05 > 0.01007,here we reject Ho
ANSWERS
---------------
null, Ho: =1.4
alternate, H1: >1.4
test statistic: 2.993
critical value: 1.895
decision: reject Ho
p-value: 0.01007

Related Questions

Navigate

• Browse (All)
• Browse A
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.