NCERT Mathematics Class 9 Exemplar Ch 14 Statistics and Probability Part 11 (For CBSE, ICSE, IAS, NET, NRA 2022)

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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
Monthly income Number of Televisions/household (in ₹)	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
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)