Question

In a random sample of 30 tires of the same type, it is found that the average life span of a tire is 36,200 miles with a standard deviation of 3,800 miles. Find the standard error of the mean.

a 126.67
b 693.78
c 9.53
d 587.24

PsyDAG
SEm = SD/√n

√30 = 5.48