Question

Please answer it fast frnds . I will follow u if u answer fast​

Answer 1

Hi mate here is your answer:-

We know that ,

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Mean = sigma(fx) / sum of the frequecies ----( 1 )

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Sum of the frequencies

= 17 + ( 5b + 3 ) + 32 + 7b - 11 +19 = 60 + 12b-------( 2 )

Sum of ( fx )

= 17 × 10 + 30 ( 5a + 3 ) + 50 × 32 + 70 ( 7a - 11 ) + ( 90 + 19 )

= 170 + 150b + 90 + 1600 + 490b - 770 + 1710

= 2800 + 640b -----( 3 )

According to the given problem ,

Mean = 50

( 3 ) / ( 2 ) = 50 [ from ( 1 ) ]

[ 2800 + 640b ] / ( 60 + 12b ) = 50

2800 + 640b = 50 ( 60 + 12b )

2800 + 640 b = 3000 + 600b

640 b - 600b = 3000 - 2800

40b = 200

b = 200 / 40

b = 5

Therefore,

Frequeny of 30 = 5a + 3 = 5 × 5 + 3 = 25 + 3 = 28

Frequecy of 70 = 7a - 11 = 7 × 5 - 11 = 35 -11 = 24

Step-by-step explanation:

Hope it helps you ❣️❣️