For a random sample of 10 men, the mean head circumference is x = 57.3 cm and the sample standard deviation is s = 2 cm. The standard error of the sample mean is:
a. 0.200
b. 0.447
c. 0.500
d. 0.632
2/sqrt(10) = 0.632
It is explained here:
http://en.wikipedia.org/wiki/Standard_error_(statistics)
To calculate the standard error of the sample mean, you need to divide the sample standard deviation by the square root of the sample size.
In this case, the sample standard deviation (s) is given as 2 cm, and the sample size is 10 men. So, the formula to calculate the standard error (SE) is:
SE = s / √n
where s is the sample standard deviation and n is the sample size.
Let's calculate it:
SE = 2 / √10 ≈ 0.632
Therefore, the standard error of the sample mean is approximately 0.632.
So the correct option is:
d. 0.632