Question

(1 point) Some shrubs have the useful ability to resprout from their roots after their tops are destroyed. Fire is a particular threat to shrubs in dry climates, as it can injure the roots as well as destroy the aboveground material. One study of resprouting took place in a dry area of Mexico. The investigation clipped the tops of samples of several species of shrubs. In some cases, they also applied a propane torch to the stumps to simulate a fire. Of 13 specimens of a particular species, 7 resprouted after fire. Estimate with 99.9% confidence the proportion of all shrubs of this species that will resprout after fire.

Interval:_____ to_____

Answer 1

Values are given as,

n= 13

x= 7

p bar = (x/n)= (7/13) = 0.538

z-critical value of 99.9% = 3.291

Calculating 99.9% confidence intrval :

0.1383

CI = 0.0829 to  0.9931

The 99.9% confidence intrval : (0.0829 <p< 0.9931)

Interpretation : we are 99.9% confident that the true proportion of all shrubs of this species that will resprout after fire is bwetween 0.0829 and  0.9931 .