Question

question 5 of 10
a 90% confidence interval is found to be (32, 48). what is the margin of error?
a. 16
b. 7.2
c. 8
d. 14.4

Explanation:

Step1: Find the midpoint (mean)

The confidence interval is \((32, 48)\). The midpoint (sample mean \(\bar{x}\)) is calculated as \(\frac{32 + 48}{2}\).

$$ \frac{32 + 48}{2} = \frac{80}{2} = 40 $$

Step2: Calculate margin of error

Margin of error \(E\) is the distance from the mean to either end of the interval. So, \(E = 48 - 40\) (or \(40 - 32\)).

$$ 48 - 40 = 8 $$

Answer:

C. 8