I have a stats exam tomorrow and I understand the material pretty well, but i sort of get confused. because my homework comes from a section, i know what formulas to use, but i took a practice test and i'm having a hard time identifying whether a problem is poisson or binomial? are there any key or specific terms i should know for each type of problem? thank you
i know how to use both poisson and binomial tables and i know the formulas for calculating means and standard deviations, i just have a hard time figuring out when i need to use the binomial formulas or when to use the poisson formulas.
Here's a few suggestions:
1. Binomial distributions are broken down into "success/failure" or "yes/no" or "agree/disagree" type of problems. You have two concepts. One example might be 42 out of 150 people agree with a particular candidate's point of view. This means 108 people out of 150 do not agree. You can convert these proportions or percentages to decimal form when using the appropriate formulas.
2. If a problem uses some sort of rate or time interval, then a Poisson distribution might be your best bet. The following is an example:
A statistics professor finds that when she schedules an office hour for student help, an average of 2.2 students arrive.
These are just a few suggestions. I hope this helps.
When determining whether a problem is Poisson or binomial, there are certain key terms and characteristics you can look out for. Here's a breakdown of each type and the key terms associated with them:
1. Poisson Distribution:
- The Poisson distribution is used to model events that occur randomly over a continuous period of time or space.
- Key terms: "rate," "average," "mean," "per unit," "per hour," "per day," "per minute," etc.
- Example problem: "What is the probability of having 4 customers arrive in a given hour at a coffee shop, knowing that the average rate of customer arrivals is 3 per hour?"
2. Binomial Distribution:
- The binomial distribution is used to model events with two possible outcomes (success or failure) over a fixed number of trials.
- Key terms: "success," "failure," "probability of success," "number of trials," "fixed number," "n," "x successes," etc.
- Example problem: "What is the probability of getting exactly 3 heads in 5 coin flips?"
To identify whether a problem is Poisson or binomial, pay attention to the specific wording and context. If the problem discusses events occurring continuously over time or space without specifying a fixed number of trials, it is likely a Poisson distribution. On the other hand, if the problem involves a fixed number of trials and two possible outcomes, it is likely a binomial distribution.
Remember that understanding the underlying concepts and characteristics of each distribution will greatly help you in identifying the appropriate distribution type. It's also important to review the formulas and equations associated with each distribution to apply them correctly.
Good luck with your exam, and don't hesitate to ask if you have any more questions!