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An Organization Selected 2400 Families at Random and Surveyed Them to Determine a Relationship Between Income Level and the Number of Vehicles in a Family. the Information Gathered is Listed in the Table Below - CBSE Class 9 - Mathematics

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Question

An organization selected 2400 families at random and surveyed them to determine a relationship between income level and the number of vehicles in a family. The information gathered is listed in the table below:-

Monthly income

(in Rs.)

Vehicles per family
0 1 2 Above 2
Less than 7000 10 160 25 0
7000 – 10000 0 305 27 2
10000 – 13000 1 535 29 1
13000 – 16000 2 469 59 25
16000 or more 1 579 82 88

Suppose a family is chosen, find the probability that the family chosen is

(i) earning Rs 10000 − 13000 per month and owning exactly 2 vehicles.

(ii) earning Rs 16000 or more per month and owning exactly 1 vehicle.

(iii) earning less than Rs 7000 per month and does not own any vehicle.

(iv) earning Rs 13000 − 16000 per month and owning more than 2 vehicles.

(v) owning not more than 1 vehicle.

Solution

Number of total families surveyed = 10 + 160 + 25 + 0 + 0 + 305 + 27 + 2 + 1 + 535 + 29 + 1 + 2 + 469 + 59 + 25 + 1 + 579 + 82 + 88 = 2400

(i) Number of families earning Rs 10000 ­− 13000 per month and owning exactly 2 vehicles = 29

Hence, required probability, P = 29/2400

 

(ii) Number of families earning Rs 16000 or more per month and owning exactly 1 vehicle = 579

Hence, required probability, P = 579/2400

 

(iii) Number of families earning less than Rs 7000 per month and does not own any vehicle = 10

Hence, required probability, P = 10/2400 = 1/240

 

(iv) Number of families earning Rs 13000 ­− 16000 per month and owning more than 2 vehicles = 25

Hence, required probability, P = 25/2400 = 1/96

 

(v) Number of families owning not more than 1 vehicle = 10 + 160 + 0 + 305 + 1 + 535 + 2 + 469 + 1 + 579 = 2062

Hence, required probability, P = 2062/2400 = 1031/1200

  Is there an error in this question or solution?

APPEARS IN

 NCERT Solution for Mathematics Class 9 (2018 to Current)
Chapter 15: Probability
Ex. 15.10 | Q: 5 | Page no. 284

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Solution An Organization Selected 2400 Families at Random and Surveyed Them to Determine a Relationship Between Income Level and the Number of Vehicles in a Family. the Information Gathered is Listed in the Table Below Concept: Probability - an Experimental Approach.
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