In a random sample of 1000 students 80 were in favor of lon

In a random sample of 1000 students , 80% were in favor of longer hours at the school. the standard error of p-hat is approx.

a. .013

b. .160

c. .640

d. .800

Solution

The standard error is

sp = sqrt(p (1-p) / n)

= sqrt(0.80*(1-0.80)/1000)

= 0.012649111

= 0.013 [OPTION A]