"The probability that a seed will sprout is 3/4. If 7 seeds are planted, find, to the nearest ten-thousandth, the probability that at least 5 will sprout."
The answer is .7564, but I don't know how to get there. I tried (3/4^5) + (3/4^6) + (3/4^7), but that doesn't work. Neither does (3/4*5)...