A student has the following grades: 86, 80, 79, 85, 70. Find the standard deviation of the grades.

Question

amistre64 · Answer

sum (x-mean)^2
--------------
      n-1

and the sqrt of that

amistre64 · Answer

or just list it in your ti83 and let it do the work

anonymous · Answer

k

amistre64 · Answer

mean = 80
sd = 6.364  rounded

anonymous · Answer

dang your a fast worker i struggle in math cause i jst dnt understand  and get headaches from it

amistre64 · Answer

86-80 =     6,   36
80-80 =     0,     0
79-80 =     1,     1
85-80 = -  5,   25
70-80 = -10, 100
                     -------
                       162

sqrt(162/(5-1))

sqrt(162/4)

sqrt(162)/2 = 6.364 rounded :)

amistre64 · Answer

$$\frac{sum.of(x-mean)^2}{(number.of.data)-1}$$