NCERT Mathematics Class 9 Exemplar Ch 14 Statistics and Probability Part 11

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Q.16. A company selected 4000 households at random and surveyed them to find out a relationship between income level and the number of television sets in a home. The information so obtained is listed in the following table:

A Company Selected 4000 Households at Random and Surveyed Them to Find Out a Relationship between Income Level and the Number of Television Sets in a Home
A company selected 4000 households at random and surveyed them to find out a relationship between income level and the number of television sets in a home
Monthly income Number of Televisions/household (in Rs)	Number of Televisions/household
	0	1	2	Above 2

Find the probability:

(i) Of a household earning per year and having exactly one television.

(ii) Of a household earning and more per year and owning 2 televisions.

(iii) Of a household not having any television.

Answer: (i) (ii) (iii)

Q.17. Two dice are thrown simultaneously 500 times. Each time the sum of two numbers appearing on their tops is noted and recorded as given in the following table:

Two Dice Are Thrown Simultaneously 500 Times. Each Time the Sum of Two Numbers Appearing on Their Tops is Noted
Two dice are thrown simultaneously 500 times. Each time the sum of two numbers appearing on their tops is noted
Sum	Frequency
2	14
3	30
4	42
5	55
6	72
7	75
8	70
9	53
10	46
11	28
12	15

If the dice are thrown once more, what is the probability of getting a sum?

(i) 3?

(ii) More than 10?

(iii) Less than or equal to 5?

(iv) Between 8 and 12?

Answer: (i) (ii) (iii) (iv)