Question

As part of a study for a new medication, a drug company samples cholesterol levels from a group of patients. The company reports that a 90% confidence interval for the cholesterol levels for the population being studied is (127.6, 168.8). What is the margin of error?
A) 18.54
B) 20.60
C) 37.08
D) 41.20

Answer 1

Answer-

The margin of error of the sample is 20.60

Solution-

We know that,

$\mu=M\pm ME$

where:

$\text{M = sample mean}\\\\\text{ME = margin of error}$

According to the question,

$168.8=M+ME\ and\ 127.6=M-ME$

Subtraction equation 2 from equation 1,

$\Rightarrow 168.8-127.6=2ME$

$\Rightarrow 2ME=168.8-127.6=41.2$

$\Rightarrow ME=\dfrac{41.2}{2}$

$\Rightarrow ME=20.60$

Therefore, the margin of error of the sample is 20.60