I flip a fair coin 17 times. Answer the following questions: a. What is the probability of getting 9 heads?
b. What is the probability of getting 2 heads?
c.. What is the probability of getting 1 tail?
d. What is the probability of getting 14 or more heads?
e. What is the probability of getting 17 tails?

A) 0.1855

B) 0.0010376

C) 0.0001297

D) 0.006363

E) 0.000007629

Step-by-step explanation:

In calculation of a probability, we normally take the ratio of the number of ways to meet a certain condition (i.e. the numerator) divided by the number of ways to pick from a pool (i.e. the denominator).

So what are the number of ways the flip of a coin 17 times can come out?

A coin has a head and tail, so each toss will have two possible results. If we toss once, we have 2 possible results. If we toss, twice we have 2² = 4 possible results.

If we toss thrice, we have 2³ = 8 possible results, etc.

Thus, for 17 tosses, we will have 2^(17) = 131072 possible results.

A) To achieve the probability of getting 9 heads, we will use combination formula;

C(n, k) = n! / (k!(n - k)!)

In this case, n = 17 and k = 9

So,

P(9 heads) = 17! / (9!(17 - 9)!) = 24310

Thus,

P(9 heads in 17 tosses of a fair coin) = 24310/131072 = 0.1855

B) Similar to A above;

P(2 heads) = 17! / (2!(17 - 2)!) = 136

Thus,

P(2 heads in 17 tosses of a fair coin) = 136/131072 = 0.0010376

C) Similar to A above;

P(1 tail) = 17! / (1!(17 - 1)!) = 17

Thus,

P(1 tail in 17 tosses of a fair coin) = 17/131072 = 0.0001297

D) probability of getting 14 or more heads?

Since, there are 17 tosses, this will be;

P(14 or more heads in 17 tosses) = P(14 heads in 17 tosses) + P(15 heads in 17 tosses) + P(16 heads in 17 tosses) + P(17 heads in 17 tosses)

P(14 heads) = 17! / (14!(17 - 14)!) = 680

P(15 heads) = 17! / (15!(17 - 15)!) = 136

P(16 heads) = 17! / (16!(17 - 16)!) = 17

P(17 heads) = 17! / (1!(17 - 17)!) = 1

Thus;

P(14 heads in 17 tosses) = 680/131072 = 0.005188

P(15 heads in 17 tosses) = 136/131072 = 0.0010376

P(16 heads in 17 tosses) = 17/131072 = 0.0001297

P(1 head in 17 tosses) = 1/131072 = 0.00000763

P(14 or more heads in 17 tosses) = 0.005188 + 0.0010376 + 0.0001297 + 0.00000763 = 0.006363

E) Similar to A above;

P(17 tails) = 17! / (17!(17 - 17)!) = 1

Thus,

P(17 tails in 17 tosses of a fair coin) = 1/131072 = 0.000007629

step-by-step explanation: