Math Background

Statistics and Probability: Tips and Tricks

  • A common mistake when collecting information about a population is collecting information from a subset of the population and claiming it reflects the views of the total population. For example, if you surveyed the general population about animal shelters, a sample drawn from people who work at animal shelters would be a biased sample, not representative of the total population.
  • Using a representative sample to predict the total population produces an estimate, not an exact answer.
  • The theoretical probability of an event and the experimental probability of an event are usually not exactly the same. Even though the probability of flipping heads is one-half, you would rarely flip a coin 20 times and get 10 heads. However, the more times you performed the event, the closer the experimental probability should come to the theoretical probability.
  • Students will often find incorrect probabilities because the outcomes they are comparing are not equally likely. For example, there are 11 sums that are possible when two 1−6 number cubes are tossed. The probability of a sum of 3 is not one-eleventh since the different sums are not equally likely.
  • Many students may need to experiment with several probability events to gain an understanding of probability.

Houghton Mifflin Math Grade 6