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

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=(41.2)/(2)`

`\Rightarrow ME=20.60`

Therefore, the margin of error of the sample is 20.60