problem with cumulative distribution function

dear team

please point out my mistake pertaining to CDF

Y is a discrete random variable

Y | 10 | 20 | 30 | 40 | 50 |

F(Y) |.23 |.45 | .78 | .96 | 1 |

FIND THE PROBABILITY THAT Y TAKES A VALUE GREATER THAN 10 BUT LESS THAN 50

SOLUTION:

P(10<Y<50)

P(Y>10)=1-P(Y<=10)=1-.23=.77
P(Y<50)= P(Y<=40) = .96

SO P(10<Y<50)=.96-.77 = .19

BUT THE ANSWER IS .73

THANKS AND REGARDS

SURESH SHARMA

 

Its CDF so the answer is only difference between P(Y=50) and P(Y=10).
Your mehod is valid for pdf.

 

Y should be BOTH greater than 10 and less than 50.
Since you are given the cdf F(y),

P(10<Y<50) = F(50) - F(10) = 0.96 -0.23 = 0.73
Why you have subtracted P(Y>10), I can't imagine!!

 

please clarify for p(Y<50), We are taking F(Y) value P(y<40) That is .96 , but for P(Y>10). We are taking F(Y) Value of P(Y<10) that is .23,

WE SHOULD TAKE THE VALUE OF P(Y<20) VALUE AS Y IS GREATER THAN 10??

THANKS
SURESH