Question

1. A heterozygous white-fruited squash plant is crossed with a yellow-fruited plant, yielding 200 seeds. of these seeds, 110 produce white-fruited plants while only 90 produce yellow-fruited plants. Are these results statistically significant? Explain using Chi-square analysis.
2. What if there were 2000 seeds and 1100 produced white-fruited plants and 900 yellow-fruited plants? Are these results statistically significant? Explain using Chi-square analysis.

Answer 1

Answer:

Part 1 , not significant

Part II, significant

Step-by-step explanation:

Given that a  heterozygous white-fruited squash plant is crossed with a yellow-fruited plant, yielding 200 seeds. of these seeds, 110 produce white-fruited plants while only 90 produce yellow-fruited plants

$H_0: Both colours are equally likely\\H_a: Both colours are not equally likely$

(Two tailed chi square test)

We assume H0 to be true and find out expected

If H0 is true expected would be 100 white and 100 yellow

Chi square = $\Sigma \frac{(O-E)^2}{E} \\=\frac{(110-100)^2}{100} +frac{(90-100)^2}{100} \\=2$

df = 1

p value = 0.152799

Since p value > 0.05 at 5% level we accept that the colours are equally likely

2)

Here observed are 1100 and 900

Expected 1000 & 1000

df = 1

Chi square = $\frac{20000}{100} =200$

p value <0.0001

These results are here statistically significant.