In: Statistics and Probability
You roll a die 48 times with the following results.
Number |
1 |
2 |
3 |
4 |
5 |
6 |
Frequency |
3 |
1 |
15 |
13 |
4 |
12 |
Use a significance level of 0.05 to test the claim that the die is
fair.
(PLEASE SHOW ALL YOUR WORK)
SOLUTION:
From given data,
Doing an observed/expected value table,
O | E | (O-E)2 / E |
3 | 8 | (3-8)2 / 8 = 3.125 |
1 | 8 | (1-8)2 / 8 = 6.125 |
15 | 8 | (15-8)2 / 8 = 6.125 |
13 | 8 | (13-8)2 / 8 = 3.125 |
4 | 8 | (4-8)2 / 8 = 2 |
12 | 8 | (12-8)2 / 8 = 2 |
Using ,
=
= 3.125+6.125+6.125+3.125+2+2
= 22.5
Degree of freedom
= 6
df = -1 = 6-1 = 5
significance level = = 0.05
Critical value
= 11.07049769
Also, the p value is
p = 0.000421
Thus, comparing and
[or, p and significance level], we REJECT THE NULL HYPOTHESIS.
There is significant evidence at 0.05 level that the die is not fair.