Question

the average number of calories in a family - size package of chocolate chip cookies is believed to be approximately normally distributed. the mean calories in a sample of 25 cookies is 69.72 with a standard deviation of 4.15. what is the standard error of mean(sem)?
0.80
1.89
0.83
2.04
3.45

Explanation:

Step1: Recall the formula for SEM

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

Step2: Substitute the given values

Given \(s = 4.15\) and \(n=25\). Then \(SEM=\frac{4.15}{\sqrt{25}}\).
Since \(\sqrt{25}=5\), we have \(SEM=\frac{4.15}{5}\).

Step3: Calculate the value

\(\frac{4.15}{5}=0.83\)

Answer:

0.83