4.3 Binompdf Function
4.3 Binompdf Function
Here you’ll learn how to use the binompdf function on a Texas Instruments graphing calculator to solve for binomial
probabilities.
Suppose you were conducting an experiment where you tossed a fair coin 75 times and recorded your results. What
is the probability that tails will come up 25 of those times?
Watch This
First watch this video to learn about the binompdf function.
MEDIA
Click image to the left for more content.CK-12 Foundation: Chapter4BinompdfFunctionA
Then watch this video to see some examples.
MEDIA
Click image to the left for more content.CK-12 Foundation: Chapter4BinompdfFunctionB
Guidance
Thebinompdf functionon the TI-84 calculator can be used to solve problems involving the probability of a precise
number of successes out of a certain number of trials. For example, if you wanted to know the probability of 45
successes out of 100 trials, you could use the binompdf function. Just like when computing the probability manually
with paper and pencil, you also have to know the probability of success for any particular trial in order to find
the answer. The syntax for the binompdf function is binompdf(n,p,a), wherenis the number of trials,pis the
probability of success for any particular trial, andais the number of successes.
Example A
A local food chain has determined that 40% of the people who shop in the store use an incentive card, such as air
miles. If 10 people walk into the store, what is the probability that half of them will be using an incentive card?
There are 10 trials, son=10.
A success is a person using a card. You are interested in 5 successes. Therefore,a=5.