Question

Question 7 Find the mean deviation about the mean for the data.

xi 5 7 9 10 12 15

fi 8 6 2 2 2 6

Class X1 - Maths -Statistics Page 360

Answer 1

we have to find out mean deviation about Median , so first of all, find the median and then we have to calculate mean deviation by using formula
$\frac{\sum{f_i(x_i-M)}}{\sum{f_i}}$

see attachment , we got ,
∑fᵢ = 26 e.g an even number
so,
$Median = \frac{\frac{Nth}{2}\: observation+(\frac{N}{2}+1)th\: observation}{2}\\\\=\frac{\frac{26th}{2} observation +(\frac{26}{2}+1)th\: observation}{2}\\\\=\frac{13th\: observation+14th\: observation}{2}\\\\=\frac{7+7}{2}\\\\=7$
hence, M = 7
now,
Mean deviation about Median
$=\frac{\sum{f_i(x_i-M)}}{\sum{f_i}}\\\\=\frac{84}{26}\\\\=3.23$

Answer 2

Step-by-step explanation:

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