Complete Question
A genetic experiment with peas resulted in one sample of offspring that consisted of 432 green peas and 164 yellow peas. a. Construct a 95% confidence interval to estimate of the percentage of yellow peas. b. It was expected that 25% of the offspring peas would be yellow. Given that the percentage of offspring yellow peas is not 25%, do the results contradict expectations?
Answer:
The 95% confidence interval is ![0.2392 < p < 0.3108](https://tex.z-dn.net/?f=0.2392%20%20%3C%20%20p%20%3C%200.3108)
No, the confidence interval includes 0.25, so the true percentage could easily equal 25%
Step-by-step explanation:
From the question we are told that
The total sample size is ![n = 432 + 164 =596](https://tex.z-dn.net/?f=n%20%20%3D%20%20432%20%2B%20164%20%3D596)
The number of offspring that is yellow peas is ![y = 432](https://tex.z-dn.net/?f=y%20%3D%20%20432)
The number of offspring that is green peas is
The sample proportion for offspring that are yellow peas is mathematically evaluated as
![\r p = \frac{ 164 }{596}](https://tex.z-dn.net/?f=%5Cr%20p%20%20%3D%20%20%5Cfrac%7B%20164%20%7D%7B596%7D)
Given the the confidence level is 95% then the level of significance is mathematically represented as
![\alpha = (100 - 95)\%](https://tex.z-dn.net/?f=%5Calpha%20%20%3D%20%20%28100%20-%2095%29%5C%25)
![\alpha = 5\% = 0.0 5](https://tex.z-dn.net/?f=%5Calpha%20%3D%20%205%5C%25%20%20%3D%20%200.0%205)
The critical value of
from the normal distribution table is
![Z_{\frac{\alpha }{2} } = 1.96](https://tex.z-dn.net/?f=Z_%7B%5Cfrac%7B%5Calpha%20%7D%7B2%7D%20%7D%20%3D%201.96)
Generally the margin of error is mathematically evaluated as
![E = Z_{\frac{\alpha }{2} } * \sqrt{\frac{\r p (1- \r p )}{n} }](https://tex.z-dn.net/?f=E%20%3D%20%20Z_%7B%5Cfrac%7B%5Calpha%20%7D%7B2%7D%20%7D%20%2A%20%5Csqrt%7B%5Cfrac%7B%5Cr%20p%20%281-%20%5Cr%20p%20%29%7D%7Bn%7D%20%7D)
=> ![E = 1.96 * \sqrt{\frac{0.275 (1- 0.275 )}{596} }](https://tex.z-dn.net/?f=E%20%3D%201.96%20%2A%20%5Csqrt%7B%5Cfrac%7B0.275%20%281-%200.275%20%29%7D%7B596%7D%20%7D)
=> ![E = 0.0358](https://tex.z-dn.net/?f=E%20%3D%20%200.0358)
The 95% confidence interval is mathematically represented as
![\r p - E < p < \r p + E](https://tex.z-dn.net/?f=%5Cr%20p%20-%20E%20%20%3C%20%20p%20%3C%20%5Cr%20p%20%2B%20E)
=> ![0.275 - 0.0358 < p < 0.275 + 0.0358](https://tex.z-dn.net/?f=0.275%20-%20%200.0358%20%20%3C%20%20p%20%3C%200.275%20%2B%20%200.0358)
=> ![0.2392 < p < 0.3108](https://tex.z-dn.net/?f=0.2392%20%20%3C%20%20p%20%3C%200.3108)