Question

if the mean of the following data is 44 find the missing frequency f class 0-20 20-40 40-60 60-80 80-100 frequency 12 f 6 7 9​

Answer 1

Answer:

08

Wires A and B are made from the same

material. Wire A has length 12m and weight

50 g, while wire B is 18 m long and weighs

40 g. Then the ratio (R / R ) of their

resistances will be: JIAO/Jr./Stage-1/2008]

(A) 16/45

(B) 4/5

(C) 8/15

(D) 4/9

Answer 2

Answer: 16

Step-by-step explanation:

Class interval       x          f                  xf

0-20                     10        12              120

20-40                   30         f                30f

40-60                   50         6               300

60-80                   70         7               490

80-100                  90         9              810

NOW

$mean = \dfrac{\sum fx}{\sum f} \\\\\Rightarrow 44= \dfrac{120+30f+300+490+810}{12+f+6+7+9} \\\\\Rightarrow 44( 34+ f) = 1720+30f \\\\\Rightarrow 1496+ 44f= 1720 +30f\\\\\Rightarrow 44f- 30f= 1720 - 1496 \\\\\Rightarrow 14f= 224\\\\\Rightarrow f= 16$

Hence, the missing frequency is 16