Question

43% of a sample of 100 visitors to a national park believes that additional funds should be used to preserve endangered species. What is the margin of sampling error for a 95% confidence interval?
A. 9.7%
B. 5.4%
C. 43%
D. 19.4%

Answer 1

Answer:

A. 9.7%

Step-by-step explanation:

margin of error:

z * $\sqrt{\frac{p(1-p)}{N} }$

n is sample size

z is the z score (for a 95% confidence interval you would use 1.96)

p is the sample proportion

to solve for 'p', remember that if a decimal value is given, use that. but if it is a whole number, then divide that number by the sample size, and substitute it into the formula.

in this case we are given 43% so 0.43.

in the formula :

1.96 * $\sqrt{\frac{0.43(1-0.43)}{100} }$

if you calculate this you get around 0.09703 this is 9.7%