Experimental probability is the probability of an event estimated from actual experimental data, calculated as the number of times the event occurred divided by the total number of trials. It approaches the theoretical probability as more trials are conducted.
You flip a coin 100 times and get 53 heads. Your experimental probability is 10053=0.53. It's based on what DID happen, not what should happen theoretically.
Showing a random 20 of 50 problems.
Example 1
easy
A student flips a coin 50 times and gets 28 heads and 22 tails. What is the experimental probability of getting heads?
Example 2
easy
A die is rolled 30 times and shows a 5 a total of 6 times. What is the experimental probability of rolling a 5?
Example 3
hard
A basketball player made 72 out of 100 free throws in practice. (a) What is her experimental free-throw probability? (b) In the next game, she attempts 15 free throws. How many would you expect her to make? (c) Why might the actual number differ from your prediction?
Example 4
easy
A basketball player makes 18 of 24 free throws in practice. What is the experimental probability of a make?
Example 5
easy
A bag is sampled with replacement 25 times; a blue marble appears 5 times. What is the experimental probability of blue?
Example 6
hard
A library tracks 480 returned books; 36 were overdue. Predict the number of overdue books out of 2000 returns.
Example 7
challenge
A weighted die rolls a 6 in 90 of 360 rolls. Assuming the rate continues, how many sixes are expected in 1000 rolls, and how much higher is this rate than a fair die's expected count?
Example 8
challenge
A spinner's experimental probability of blue is 83 from 160 spins. The next 40 spins give 20 blues. What is the combined experimental probability of blue?
Example 9
medium
A bag contains an unknown number of red and blue marbles. In 80 draws (with replacement), 52 red and 28 blue marbles were drawn. (a) Estimate the probability of drawing a red marble. (b) If there are 20 marbles total, estimate how many are red.
Example 10
hard
Two students each track a coin: Alex flips 30 times and sees 20 heads; Bri flips 300 times and sees 165 heads. Whose experimental probability is closer to the theoretical 21?
Example 11
easy
Out of 150 light bulbs tested, 6 were defective. What is the experimental probability that a bulb is defective?
Example 12
medium
A die showed these counts in 60 rolls: 1:9, 2:11, 3:10, 4:8, 5:12, 6:10. What is the experimental probability of rolling a 5?
Example 13
hard
If the experimental probability of an event after 240 trials is 245, how many successes were recorded?
Example 14
easy
A coin is flipped 20 times and lands heads 12 times. What is the experimental probability of heads?20 flips: 12 heads, 8 tails
Example 15
hard
A coin lands heads 600 times in 1000 flips. If the next 200 flips continue at the same rate, how many additional heads would you predict?
Example 16
hard
A trial set: 1200 spins, red 280, blue 360, green 560. Find the experimental probability of NOT green.1200 spins — counts per color; find P(not green)
Example 17
medium
A spinner lands on green 18 times in 45 spins. Based on this, how many green landings are expected in 100 spins?
Example 18
medium
Over 200 trials an event occurs 50 times. What is the experimental probability as a decimal?
Example 19
hard
A die rolled 250 times shows a 6 forty-five times. If the die is fair, what is the difference between observed and theoretical probability?
Example 20
easy
A school survey finds 90 of 300 students walk to school. What is the experimental probability a student walks?