## StatCrunch – Binomial Probability Calculator

I just finished up a short unit on binomial probabilities with my Intro Stat class, using StatCrunch as the primary method of calculating probabilities. To access the calculator in StatCrunch, click the Stat button, and select Binomial from the Calculator option.

Here is the interface.

Enter the number of trials in the box labeled n and the probability of success on one trial in the box labeled p. When it comes to the number of successes, you have several options: <= (for $\le$), => (for $\ge$), <, >, or =. Enter the appropriate value for x once you have selected the option you need and press Compute.

By the way, if you need to find something like $P(3 \le x \le 7)$, you will have to do it in 2 steps. (StatCrunch does not have a “between 3 & 7” option.) First, find $P(x \le 7)$, and then subtract the result you get from $P(x<3)$.

One of the features I like is the graphical display of the probabilities. The values of x that you are working with are displayed with red bars.

By making the actual calculations easier, I find that we can spend more time on challenging problems. My students also have a better understanding of the big picture, instead of getting lost in the weeds with their calculators and 20 pages of binomial probability tables.

– George

I am a math instructor at College of the Sequoias in Visalia, CA. If there’s a particular topic you’d like me to address, or if you have a question or a comment, please let me know. You can reach me through the contact page on my website – http://georgewoodbury.com.