Answer:
D) The revised interval is wider than the original interval because the corect sample proportion is closer to 0.5 than the mis-calculated proportion is.
Step-by-step explanation:
In a sample with a number n of people surveyed with a probability of a success of [tex]\pi[/tex], and a confidence level of [tex]1-\alpha[/tex], we have the following confidence interval of proportions.
[tex]\pi \pm z\sqrt{\frac{\pi(1-\pi)}{n}}[/tex]
In which
z is the zscore that has a pvalue of [tex]1 - \frac{\alpha}{2}[/tex].
The margin of error is:
[tex]M = z\sqrt{\frac{\pi(1-\pi)}{n}}[/tex]
The larger the closer to 0.5 the value of [tex]\pi[/tex], the larger the margin of error and the wider the interval is.
A biologist studying trees constructed the confidence interval (0.14, 0.20)
This means that the estimate used was of:
[tex]\pi = \frac{0.14 + 0.2}{2} = \frac{0.34}{2} = 0.17[/tex]
The correct sample proportion was 0.27.
With [tex]\pi = 0.27[/tex], the margin of error is larger as 0.27 is closer to 0.5 than 0.17. Thus, the revised interval will be wider, and the correct answer is given by option D.