Question

What is the standard deviation for 212,249,212,248,239,212,216,234,248

Answer 1

Answer:

15.90  

Step-by-step explanation:

The formula for standard deviation, σ, of a population is

$\sigma = \sqrt{\frac{1 }{N }\sum_{i=1}^{N}(x_{i}-\mu)^{2}}$

We can use a table to organize the calculations.

    x        x - µ    (x - µ)²

  212         -18        324

  249         19        361

  212         -18        324

  248         18        324

  239          9           81

  212        -18         324

  216        -14         196

  234          4           16

  248         18        324

2070                   2274

Sum= 2070

N = 9

µ = Sum/N = 2070/9 = 230

$\sigma = \sqrt{\frac{1 }{9 }\times2274} =\sqrt{252.7} = 15.90$