In: Statistics and Probability
A genetic experiment with peas resulted in one sample of offspring that consisted of
426 green peas and 168 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?
a. Construct a 95% confidence interval. Express the percentages in decimal form.
nothingless than<p less than<nothing
(Round to three decimal places as needed.)
b. Given that the percentage of offspring yellow peas is not 25%, do the results contradict expectations?
Yes, the confidence interval does not include 0.25, so the true percentage could not equal 25%
No, the confidence interval includes 0.25, so the true percentage could easily equal 25%
Solution :
Given that,
n = 426 + 168 = 594
x = 168
a) Point estimate = sample proportion = = x / n = 168 / 594 = 0.283
1 - = 1 - 0.283 = 0.717
At 95% confidence level
= 1 - 95%
=1 - 0.95 =0.05
/2
= 0.025
Z/2
= Z0.025 = 1.96
Margin of error = E = Z / 2 * (( * (1 - )) / n)
= 1.96 (((0.283 * 0.717) / 594 )
= 0.036
A 95% confidence interval for population proportion p is ,
- E < p < + E
0.283 - 0.036 < p < 0.283 + 0.036
( 0.247 < p < 0.319)
b) No, the confidence interval includes 0.25, so the true percentage could easily equal 25%