Question

in a clinical trial investigating the effectiveness of a new drug in reducing blood pressure, a sample of 16 participants was selected. the mean reduction in blood pressure was 4.7 mmhg, and the standard deviation was 7.1 mmhg. calculate the standard error of the mean (sem) for the change in blood pressure within this sample. include three decimal places.
a. 2.723
b. 0.444
c. 1.775
d. 1.825

Explanation:

Step1: Recall SEM formula

The formula for the Standard Error of the Mean is $\text{SEM} = \frac{s}{\sqrt{n}}$, where $s$ is the sample standard deviation, and $n$ is the sample size.

Step2: Identify given values

We have $s = 7.1$ mmHg, $n = 16$.

Step3: Calculate square root of sample size

$\sqrt{n} = \sqrt{16} = 4$

Step4: Compute SEM

$\text{SEM} = \frac{7.1}{4} = 1.775$

Answer:

c. 1.775