Question

Example

a) On this example we will examine the probability a couple who has 8 children and has exactly 5 boys.

b) Next we will look at the probability that they have more than 5 boys.

c) Finally we will look at the probability that they have at most 5 boys.

Assume a .5 chance of having a boy.

Solution can be solved using excel.

a) On this example we will examine the probability a couple who has 8 children has exactly 5 boys.

Type this in an excel cell

=binom.dist(5,8,.5,False)

and then hit enter

.21875 would be the answer

b) Next we will look at the probability that they have more than 5 boys.

Type this in an excel cell

=1-binom.dist(5,8,.5,True)

and then hit enter

.144531 would be the answer

c) Finally we will look at the probability that they have at most 5 boys.

Assume a .5 chance of having a boy.

Type this in an excel cell

=binom.dist(5,8,.5,True)

and hit enter

.855469 would be the answer

Instructions:

For your post you will make up a problem similar to this example. Try to have at least 3 scenarios. You will not solve your own problem.

Answer 1

Problem statement:

(a) Consider a problem where we have to toss an unbiased coin and we have to find the probability of ending up with exactly 3 Heads in 9 trials.

(b) Then, we will look at the probability of ending up with more than 3 Heads.

(c) Finally, we will look at the probability of ending up with at most 3 Heads.

The following problem can be solved using Excel.

Solution:

Assume a .5 chance of getting a Head on tossing a coin, each time.

(a) Here, we will examine the probability of ending up with exactly 3 Heads in 9 trials.

To get the desired result, type this in an Excel cell and hit Enter:

=binom.dist(3,9,.5,False)

The required answer is:

0.164063

(b) Now, we will look at the probability of ending up with more than 3 Heads in 9 trials.

To get the desired result, type this in an Excel cell and hit Enter:

=1-binom.dist(3,9,.5,True)

The required answer is:

0.746094

(c) Now, we will look at the probability of ending up with at most 3 Heads in 9 trials.

To get the desired result, type this in an Excel cell and hit Enter:

=binom.dist(3,9,.5,True)

The required answer is:

0.253906

Hope this helps!