Question

The income of a group of 10000 person we
re found to be normally distributed with mean rs 750 per month and sd is rs 50 show that this group person had about 95% income exceeding rs 668 and only 5% had income exceeding rs 832 area corresponding to x is equal to 668 is equal to 0.4495

Answer 1

Answer:

= P((y - μ)/σ > - 1.6449) = 95%  

= P(y - μ > - 1.6449σ) = 95%  

= P(y > μ - 1.6449σ) = 95%  

= P(y > 750 - 1.6449(50)) = 95%  

= P(y > 667.755) = 95%  

= P(y > 668) ≈ 95%  

= P((y - μ)/σ > 1.6449) = 5%  

= P(y - μ > + 1.6449σ) = 5%  

= P(y > μ + 1.6449σ) = 5%  

= P(y > 750 + 1.6449(50)) = 5%  

= P(y > 832.245) = 5%  

=> P(y > 832) ≈ 5%