Question 272155
You flip a fair coin 10 times. What is the probability that it lands on heads exactly 7 times?
P(x = 7) = 10C7(1/2)^7(1/2)^3 = 0.1172
--------------------------------------------- 
What is the probability that it lands on heads at least 7 times?
P(7<= x <=10) = 1 - binomcdf(10,0.5,6) = 0.1719
---------------------------------------------------
Cheers,
Stan H.