In: Statistics and Probability
The data presented in the table below resulted from an experiment in which seeds of 4 different types were planted and the number of seeds that germinated within 4 weeks after planting was recorded for each seed type.
At the .05 level of significance, is the proportion of seeds that germinate dependent on the seed type?
Seed Type |
Observed Frequencies |
||
Germinated |
Failed to Germinate |
||
1 |
39 |
9 |
|
2 |
54 |
34 |
|
3 |
88 |
63 |
|
4 |
57 |
42 |
No, the proportion of seeds that germinate are not dependent on the seed type because the p-value = 0.0132.
No, the proportion of seeds that germinate are not dependent on the seed type because the p-value = 0.0265.
Yes, the proportion of seeds that germinate dependent on the seed type because the p-value = 0.0265.
Yes, the proportion of seeds that germinate dependent on the seed type because the p-value = 0.0132.
Null hypothesis : Ho : Proportion of seeds that germinate are not dependent on the seed type
Alternative Hypothesis : Ha: Proportion of seeds that germinate are dependent on the seed type
- Test for association
Test Statistic
O : Observed Frequency
E: Expected Frequency
Given,
Observed Frequencies : O
Seed type | Germinated | Failed to Germinate | Row Total |
1 | 39 | 9 | 48 |
2 | 54 | 34 | 88 |
3 | 88 | 63 | 151 |
4 | 57 | 42 | 99 |
Column Total | 238 | 148 | Grand Total =386 |
E: Expected Count/Frequency: E
Seed Type | Germinated | Failed to Germinate |
1 | (48*238) / 386 | (48*148) / 386 |
2 | (88*238) / 386 | (88*148) / 386 |
3 | (151*238) / 386 | (151*148) / 386 |
4 | (99*238) / 386 | (99*148) / 386 |
E :
Seed Type | Germinated | Failed to Germinate |
1 | 29.5959 | 18.4041 |
2 | 54.2591 | 33.7409 |
3 | 93.1036 | 57.8964 |
4 | 61.0415 | 37.9585 |
O | E | O-E | (O-E)2 | (O-E)2/E |
39 | 29.5959 | 9.4041 | 88.4379 | 2.9882 |
9 | 18.4041 | -9.4041 | 88.4379 | 4.8053 |
54 | 54.2591 | -0.2591 | 0.0671 | 0.0012 |
34 | 33.7409 | 0.2591 | 0.0671 | 0.0020 |
88 | 93.1036 | -5.1036 | 26.0470 | 0.2798 |
63 | 57.8964 | 5.1036 | 26.0470 | 0.4499 |
57 | 61.0415 | -4.0415 | 16.3333 | 0.2676 |
42 | 37.9585 | 4.0415 | 16.3333 | 0.4303 |
Total | 9.2243 |
Degrees of freedom = (Number of rows -1)(Number of columns - 1) = (4-1)x(2-1) =3
For 3 degrees of freedom,
p-value = 0.0265
Given, level of significance: = 0.05
As p-value : 0.0265 < level of significance: : 0.05 ; Reject the null hypothesis;
There is sufficient evidence to conclude that Proportion of seeds that germinate are dependent on the seed type.
is the proportion of seeds that germinate dependent on the seed type?
Answer :
Yes, the proportion of seeds that germinate dependent on the seed type because the p-value = 0.0265.