Math Question and Answers


Question and Answers Forum

All Questions Topic List
Algebra Questions
Previous in All Question Next in All Question
Previous in Algebra Next in Algebra
Question Number 14354 by tawa tawa last updated on 30/May/17

	Answered by mrW1 last updated on 31/May/17

	$2 .$ $m e a n = (60 + 62 + 65 + 68 + 79) / 5 = 66.8$ $t h e n u m b e r c l o s e t o m e a n i s 68 k g .$ $\Rightarrow D$ $3 .$ $4! \times 3! \times 4! \times 4! \times 2! = 165888$ $\Rightarrow D$
	Commented by mrW1 last updated on 31/May/17

	$E x p l a n a t i o n t o Q 2 .$ $n v a l u e s : x_{i}$ $m e a n m = \frac{1}{n} \underset{i = 1}{\sum^{n}} x_{i}$ $s u m o f s q u a r e d d e v i t i o n f r o m a v a l u e u$ $i s$ $S = \underset{i = 1}{\sum^{n}} {(x_{i} - u)}^{2} = \underset{i = 1}{\sum^{n}} (x_{i}^{2} - 2 {u x}_{i} + u^{2})$ $= \underset{i = 1}{\sum^{n}} x_{i}^{2} - 2 u \underset{i = 1}{\sum^{n}} x_{i} + \underset{i = 1}{\sum^{n}} u^{2}$ $= \underset{i = 1}{\sum^{n}} x_{i}^{2} - 2 u n m + {n u}^{2}$ $= \underset{i = 1}{\sum^{n}} x_{i}^{2} - {n m}^{2} + {n m}^{2} - 2 u n m + {n u}^{2}$ $= \underset{i = 1}{\sum^{n}} x_{i}^{2} - {n m}^{2} + n {(u - m)}^{2}$ $\Rightarrow t h e s m a l l e r t h e d i f f e r e n c e b e t w e e n$ $u a n d m (i . e . ∣ u - m ∣), t h e s m a l l e r t h e s u m o f$ $s q u a r e d d e v i t i o n .$
	Commented by tawa tawa last updated on 31/May/17

	$God bless you sir . Longest time sir .$
Terms of Service
Privacy Policy
Contact: info@tinkutara.com

Question and Answers Forum