SOLUTION: Find the probability that in a class of 28 students exactly four were born in each of the seven days of the week.
Algebra ->
Probability-and-statistics
-> SOLUTION: Find the probability that in a class of 28 students exactly four were born in each of the seven days of the week.
Log On
Question 346056: Find the probability that in a class of 28 students exactly four were born in each of the seven days of the week. Answer by edjones(8007) (Show Source):
You can put this solution on YOUR website! For eaxctly four on Mon. expand the binomial (a+b)^28 where a=1/7 and b=6/7
20475(1/7)^4(6/7)^24=.2109
Tues: 10626(1/6)^4(5/6)^20=.2139 Remember 4 less students and 1 less day
Wed: 4845(1/5)^4(4/5)^16=.2182
Thurs: 1820(1/4)^4(3/4)^12=.2252
Fri: 495(1/3)^4(2/3)^8=.2384
Sat: 70(1/2)^4(1/2)^4=.2734
Sun=1.000
Multiply all seven numbers = .0001445
.
Let me know if there is an easier way of doing this.
.
Ed
