Question

Gardeners on the west coast of the United States are investigating the difference in survival rates of two flowering plants in drought climates. Plant A has a survival rate of 0.75 and plant B has a survival rate of 0.46. The standard error of the difference in proportions is 0.085. What is the margin of error for a 99% confidence interval? Use critical value z = 2.576.

MOE =

Answer 1

Solution :

Given that,

= 0.085

At 99% confidence level

= 1 - 99%

=1 - 0.99 =0.01

/2 = 0.005

Z/2 = Z0.005 = 2.576

Margin of error = E = Z / 2 *

MoE = 2.576 * 0.085

MoE = 0.219