Question

Which of these expressions entered into a graphing calculator will return the probability that 10 or fewer heads come up when flipping a coin 45 times?

A. binomcdf(45, 10, 0.5)
B. binomcdf(10, 45, 0.5)
C. binomcdf(10, 0.5, 45)
D. binomcdf(45, 0.5, 10)

Answer 1

oh ok so it would be binomcdf( 500, 0.5, 450) so the end result would be 450?

Answer 2

Option: D is the correct answer.

D. binomcdf(45, 0.5, 10)

Explanation:

We are asked to find the probability that 10 or fewer heads come up when flipping a coin 45 times.

We know that the binomial probability distribution function of k successes for n experiments is given by:

`P(X=k)=n_C_k\cdot p^k\cdot (1-p)^(n-k)`

Here we have: n=10

p=flipping of a head=1/2=0.5

k=0,1,2,3,4,5,6,7,8,9,10

i.e. r=10

Now binomcdf is a function which is defined as:

`binomcdf(n,p,r)=P(X\leq r)=\sum_(k=0)^(r) P(X=k)`

Hence, by putting the values of n,p and r in the function we have:

The binomcdf function is given by:

D. binomcdf(45, 0.5, 10)