If the mean of the following data is 20.2, then find the value of p. xi 10 15 20 25 30 fi 6 8 p 10 6 - Algebra

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Sum

If the mean of the following data is 20.2, then find the value of p.

xi 10 15 20 25 30
fi 6 8 p 10 6
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Solution

We have,

`bb(x_i)` `bb(f_i)` `bb(x_i f_i)`
10 6 60
15 8 120
20 p 20p
25 10 250
30 6 180
  Total N = (30 + p) Total sum = (610 + 20 p)

since, mean = 20.2

⇒ `(610 + 20"p")/(30 + "p")` = 20.2

⇒ 610 + 20p = 20.2 (30 + p)

⇒ 610 + 20p = 606 + 20.2p

⇒ 20.2p - 20p = 610 - 606

⇒ 0.2p = 4

⇒ p = `4/0.2`

⇒ p = 20

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Chapter 7: Statistics - Problem Set 7 [Page 217]

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Balbharati Mathematics 1 Algebra 9th Standard Maharashtra State Board
Chapter 7 Statistics
Problem Set 7 | Q (5) | Page 217

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