Question

a math 7 module has 12 pages with the following numbers of words 301,298,314,327,296,287,271,326,316,333,354 and 285.what is the standard number of words per pages

Answer 1

Mean of population  = 

$$\mu=\dfrac{1}{12}(301+298+314+327+296+287$$ $$+271+326+316+333+354+285)=309$$

Variance of population 

$$\sigma^2=\dfrac{\Sigma(x_i-\bar{x})^2}{n}$$

$$=\dfrac{1}{12}(64+121+25+324+169+484$$

$$+1444+289+49+576+2025+576)=\dfrac{3073}{6}$$

$$\sigma=\sqrt{\sigma^2}=\sqrt{\dfrac{3073}{6}}\approx22.6311$$