Question

39. Weekly wages of workers in a factory are as follows:
Weekly wages in ) 325-350 350-375 375 -400 400 -425 425- 450
No. of workers
5 I 15 I 10 I 20 I 15
5
Find the probability that a worker selected at random earns:
a) 400 or more
b) 375 or more but less than 425.
b) At least 375.
d) up to 400​

Answer 1

The probabilities are 0.538,0.462,0.692,0.462 respectively.

• The total no of workers are 5+15+10+20+15=65
• The no of workers with weekly wages 400 or more = 35(20+15)
• The no of workers with weekly wages 375 or more but less than 425 = 30(10+20)

• The no of workers with weekly wages at least 375  = 45 (10+20+15)
• The no of workers with weekly wages up to 400 = 30(5+15+10)

The probability that worker earns :

1. 400 or more = 35/65 = 0.538
2. 375 or more but less than 425 = 30/65 = 0.462
3. at least 375 = 45/65 = 0.692
4. up to 400 = 30/65 = 30/65