A student scores the following marks in five tests : 54,45,41,43,57 . His score is not known for the sixth test. If the mean score is 48 in six tests, then the standard deviation of marks in six tests is

Step-by-step solution

Let students' sixth test score be x , aligned & Mean =48 & 54+45+41+43+57+x 6 =48 & x=48 aligned aligned & Standard deviation & = 1 n (x_ i - x )^2 = & 1 6 [ (6^2+(-3)^2+(-7)^2+(-5)^2+(9)^2 ) ] = & 200 6 = & 10 3 aligned