In: Statistics and Probability
A random sample found that forty percent of 50 Americans were satisfied with the gun control laws in 2017. Compute a 97% confidence interval for the true proportion of Americans who were satisfied with the gun control laws in 2017. Fill in the blanks appropriately.
A 97% for the true proportion of Americans who were satisfied with the gun control laws in 2017 is:
Answer= (___ ,___ ) (Keep 3 decimal places)
SOLUTION:
From given data,
A random sample found that forty percent of 50 Americans were satisfied with the gun control laws in 2017. Compute a 97% confidence interval for the true proportion of Americans who were satisfied with the gun control laws in 2017. Fill in the blanks appropriately.
Sample proportion = = 40% = 40/100 =
0.40
=
50
97% confidence interval
97% = 97/100 = 0.97
= 1-0.97 =
0.03
/2 = 0.03/2 =
0.015
Critical value:
z/2 =
z0.015 = 2.1701
A 97% for the true proportion of Americans who were satisfied with the gun control laws in 2017 is:
97% C.I = z
/2 *
sqrt(
*(1-
) /
)
97% C.I = 0.40 2.1701*
sqrt(0.40*(1-0.40) / 50)
97% C.I = 0.40 0.1503489
97% C.I =( 0.40 -0.1503489 , 0.40 +0.1503489)
97% C.I =(0.249 , 0.550)