Suppose the average math SAT score for students enrolled at local community college is 490.4 with a standard deviation of 63.7. A random sample of 49 students has been selected. The standard error of the mean for this sample is
A) 10.6
B) 9.1
C) 63.7
D) 28.4

Respuesta :

Answer:

The standard error of the mean for this sample is 9.1.

Step-by-step explanation:

We are given that the average math SAT score for students enrolled at local community college is 490.4 with a standard deviation of 63.7.

A random sample of 49 students has been selected.

Since we know that the confidence interval is created by the given formula;

Suppose we have to calculate 95% confidence interval;

So, 95% Confidence interval = Sample mean [tex]\pm[/tex] Margin of error

where, Sample mean = [tex]\bar X[/tex] = 490.4

Margin of error = [tex]Z_\frac{\alpha}{2} \times \frac{\sigma}{\sqrt{n} }[/tex]

Here, [tex]\sigma[/tex] = standard deviation = 63.7

          n = sample of students = 49

So, Standard error formula is given by = [tex]\frac{\sigma}{\sqrt{n} }[/tex]

                                                                  = [tex]\frac{63.7}{\sqrt{49} }[/tex] = 9.1

Therefore, standard error of the mean for this sample is 9.1.