Question

question 7 of 40
an 80% confidence interval is found to be (12, 20). what is the margin of error?
a. 3.2
b. 4
c. 8
d. 6.4

Explanation:

Step1: Calculate interval width

Width = Upper bound - Lower bound = $20 - 12 = 8$

Step2: Find margin of error

Margin of error = $\frac{\text{Width}}{2} = \frac{8}{2} = 4$

Answer:

B. 4