getcalc.com's solved example with solution to find what is the probability of getting 2 Heads in 4 coin tosses.
P(A) = 11/16 = 0.69 for total possible combinations for sample space S = {HHHH, HHHT, HHTH, HHTT, HTHH, HTHT, HTTH, HTTT, THHH, THHT, THTH, THTT, TTHH, TTHT, TTTH, TTTT} & successful events for getting at least 2 heads A = {HHHH, HHHT, HHTH, HHTT, HTHH, HTHT, HTTH, THHH, THHT, THTH, TTHH} for an experiment consists of four independent events.
for 2 Heads in 4 Coin Flips | ||
---|---|---|
Atleast 2 Heads | Exactly 2 Heads | |
Total Events n(S) | 16 | 16 |
Success Events n(A) | 11 | 6 |
Probability P(A) | 0.69 | 0.38 |
The above probability of outcomes applicable to the below questions too.
The ratio of successful events A = 11 to the total number of possible combinations of a sample space S = 16 is the probability of 2 heads in 4 coin tosses. Users may refer the below solved example work with steps to learn how to find what is the probability of getting at-least 2 heads, if a coin is tossed four times or 4 coins tossed together. Users may refer this tree diagram to learn how to find all the possible combinations of sample space for flipping a coin one, two, three or four times.
Solution
Step by step workout
step 1 Find the total possible events of sample space S
S = {HHHH, HHHT, HHTH, HHTT, HTHH, HTHT, HTTH, HTTT, THHH, THHT, THTH, THTT, TTHH, TTHT, TTTH, TTTT}
S = 16
step 2 Find the expected or successful events A
A = {HHHH, HHHT, HHTH, HHTT, HTHH, HTHT, HTTH, THHH, THHT, THTH, TTHH}
A = 11
step 3 Find the probability
P(A) = Successful Events/Total Events of Sample Space
= 11/16
= 0.69
P(A) = 0.69
0.69 is the probability of getting 2 Heads in 4 tosses.