A random group of students was asked to name their favorite type of music. The c
ID: 3290717 • Letter: A
Question
A random group of students was asked to name their favorite type of music. The campus, radio station believes that 18% of the students prefer rap, 22% prefer rock, 15% prefer country, 17% prefer new age, and 28% prefer oldies. Is there evidence to reject this hypothesis at = 0.05? There is not evidence to reject the claim that the favorite music types are distributed is claimed because the test value 9.488 > 7.240 There is evidence to reject the claim that the favorite music types are distributed as claimed because the test value 7.240 7.240Explanation / Answer
Solution
Let Oi and Ei be respectively the observed (given) and
expected frequency in the ith class.
Then, Ei = n x pi, where pi = expected probability
which is estimated by proportion or percentage in the ith class
Claim: Favourite music types are as claimed by campus radio station.
Hypotheses:
Null H0: Distribution of Favourite music types is as claimed by campus radio station
Vs
Alternative HA: H0 is false.
Test statistic:
2 = [1,5]{(Oi - Ei)2/Ei}.
Computations
Class i
1
2
3
4
5
Total
Oi
21
25
19
18
16
99
pi
0.18
0.22
0.15
0.17
0.28
1
Ei
17.82
21.78
14.85
16.83
27.72
99
Chi-square
0.567475
0.476051
1.159764
0.081337
4.955209
7.239837
CHECK: sumOi must equal sumEi.
Done.
Chi-square =
7.23983
Distribution, Critical Value
Under H0, 2 ~ 2n – 2, where n = number of classes = 5.
Critical value = upper % point of 2n – 2.
Given = 0.05, 2crit= 23, 0.05= 7.815.
Decision Criterion (Rejection Region)
Reject H0, if 2cal > 2crit
Decision:
Since 2cal < 2crit, H0 is accepted.
Conclusion:
There is sufficient evidence to support the claim that the Favourite music types are as claimed by campus radio station. Or, put in a different way but meaning the same, ‘There is not sufficient evidence to reject the claim that the Favourite music types are as claimed by campus radio station.’ Second Option
DONE
Let Oi and Ei be respectively the observed (given) and
expected frequency in the ith class.
Then, Ei = n x pi, where pi = expected probability
which is estimated by proportion or percentage in the ith class
Related Questions
drjack9650@gmail.com
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.