Tamil Nadu Board of Secondary EducationSSLC (English Medium) Class 10th

# A teacher asked the students to complete 60 pages of a record notebook. Eight students have completed only 32, 35, 37, 30, 33, 36, 35 and 37 pages. Find the standard deviation of the pages yet to be - Mathematics

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A teacher asked the students to complete 60 pages of a record notebook. Eight students have completed only 32, 35, 37, 30, 33, 36, 35 and 37 pages. Find the standard deviation of the pages yet to be completed by them.

#### Solution

The remaining number of pages to be completed is 60 – 32, 60 – 35, 60 – 37, 60 – 30, 60 – 33, 60 – 36, 60 – 35 and 60 – 37

The pages to be completed are, 28, 25, 23, 30, 27, 24, 25, and 23

Arrange in ascending order we get, 23, 23, 24, 25, 25, 27, 28 and 30

 xi xi2 23 529 23 529 24 576 25 625 25 625 27 729 28 784 30 900 sumx_"i" = 205 sumx_"i"^2 = 5297

Here n = 8, sumx_"i" = 205, sumx_"i"^2 = 5297

Standard deviation (σ) = sqrt((sumx_"i"^2)/"n" - ((sumx_"i")/"n")^2

= sqrt(5297/8 - (205/8)^2

= sqrt(662.13 - 42025/64)

= sqrt(662.13 - 656.64)

= sqrt(5.49)

= 2.34

Standard deviation (σ) = 2.34

Is there an error in this question or solution?

#### APPEARS IN

Samacheer Kalvi Mathematics Class 10 SSLC Tamil Nadu State Board
Chapter 8 Statistics and Probability
Exercise 8.1 | Q 4 | Page 313
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