Answer:
1.691
Step-by-step explanation:
Standard error of the mean is expressed as SEM = S/√n
S is the population standard deviation
n is the sample size (number of observation)
Given S = 27 and n = 255
SEM = 27/√255
SEM = 27/15.97
SEM = 1.691
Hence the standard error of the mean is 1.691
