Question

the mean reaction time for 52 participants is 240 msec, with a sd of 85.8. what is the sem?
answer:

Explanation:

Step1: Recall SEM formula

The standard error of the mean (SEM) is calculated as $\text{SEM} = \frac{s}{\sqrt{n}}$, where $s$ is the sample standard deviation, and $n$ is the sample size.

Step2: Plug in given values

Here, $s = 85.8$, $n = 52$. First calculate $\sqrt{52} \approx 7.2111$.
Then compute $\text{SEM} = \frac{85.8}{7.2111}$

Step3: Calculate final value

$\frac{85.8}{7.2111} \approx 11.90$

Answer:

11.90