Question

given the data: 21, 31, 26, 24, 28, 26 this is a 3 part question: part - 2: find the standard deviation of 21, 31, 26, 24, 28, 26. s.d.≈26 s.d.≈3.1

Explanation:

Step1: Calculate the mean

$\bar{x}=\frac{21 + 31+26+24+28+26}{6}=\frac{156}{6}=26$

Step2: Calculate the squared - differences

$(21 - 26)^2=(-5)^2 = 25$, $(31 - 26)^2=(5)^2 = 25$, $(26 - 26)^2=(0)^2 = 0$, $(24 - 26)^2=(-2)^2 = 4$, $(28 - 26)^2=(2)^2 = 4$, $(26 - 26)^2=(0)^2 = 0$

Step3: Calculate the variance

$S^2=\frac{25+25 + 0+4+4+0}{6}=\frac{58}{6}\approx9.67$

Step4: Calculate the standard deviation

$S=\sqrt{9.67}\approx3.1$

Answer:

$S.D.\approx3.1$