A coin is tossed 10 times. Find the chance of getting exactly 5 heads. Find the chance of obtaining
between 4 and 6 heads inclusive.

a)
> 0.5^10 * choose(10,5)
[1] 0.2460938

b)
> 0.5^10 * choose(10,5)
[1] 0.2460938
> 0.5^4*0.5^6 * choose(10,4)
[1] 0.2050781
> 0.5^10 * choose(10,4)
[1] 0.2050781
> 0.5^10 * choose(10,6)
[1] 0.2050781
> 2*0.2050781+0.2460938
[1] 0.65625