Question 8 The distance (in km) of 40 engineers from their residence to their place of work were found as follows. 5 3 10 20 25 11 13 7 12 31 19 10 12 17 18 11 32 17 16 2 7 9 7 8 3 5 12 15 18 3 12 14 2 9 6 15 15 7 6 12 What is the empirical probability that an engineer lives: (i) less than 7 km from her place of work? (ii) more than or equal to 7 km from her place of work? (iii) within km from her place of work?
Class 9 - Math - Probability Page 284
Answers
Probability is the study of the chances of events happening.
Event:
A Possible outcome or combination of outcomes is called event.
The probability of happening our event always lies from 0 to 1.
The sum of all the probabilities of all possible outcomes of an experiment is 1.
Required probability=number of trials in which the event E has happened/Total number of trials
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Total numbers of engineers live= 40
(i) Numbers of engineers living less than 7 km from her place of work = 9
Required probability,P(less than 7 km)= 9/40
ii)Numbers of engineers whose residence is more than or equal to 7 km from their place of work = 40 – 9 = 31
Required probability,P(more than or equal to 7 km) = 31/40
(iii) Numbers of engineers whose residence within 1/2 km from their place of work = 0
Required probability,P(within 1/2 km) = 0/40 = 0
P(less than 7 km)=9/40
P(more than or equal to 7 km)=31/40
P(within 1/2 km)=0
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Hope this will help you..
Total number of engineer =40
1) Number of engineer living less than 7 km from their place of work =9
Probability=9/40
2(Number of engineer living more than or equal to 7 km from her place of work
==31
So,that Probability=31/40
3) Number of engineer lives within 1/2 km from her place of work=0
So that Probability =0/40
= It mean zero. (0)
Hope it is helpful...