Teaching mathematics
Teaching mathematics

Start this free course now. Just create an account and sign in. Enrol and complete the course for a free statement of participation or digital badge if available.

Free course

Teaching mathematics

5.5 Estimating probability

When you don’t know enough about a population to calculate the theoretical probability, you can estimate the probability using the relative frequency from a sample of the population.

For example:a bag contains some red and some blue sweets. There are 7 red sweets and 3 blue sweets.

Amrit does not know how many sweets of each colour are in the bag.

She took out one sweet from the bag, recorded its colour and replaced it.

Amrit did this 10 times and found that she picked a red sweet 5 times. This gave the relative frequency five divided by 10.

At this point Amrit predicted that the probability of picking a red sweet was five divided by 10, or ½. Therefore, if there were 10 sweets in the bag in total, she thought there were probably 5 red sweets.

In order to get a more accurate estimate of the probability, Amrit should repeat the experiment many more times.

As we discussed earlier, the more times an experiment is carried out, the closer the relative frequency will be to the theoretical probability.

TM_1

Take your learning further

Making the decision to study can be a big step, which is why you'll want a trusted University. The Open University has 50 years’ experience delivering flexible learning and 170,000 students are studying with us right now. Take a look at all Open University courses.

If you are new to university level study, find out more about the types of qualifications we offer, including our entry level Access courses and Certificates.

Not ready for University study then browse over 900 free courses on OpenLearn and sign up to our newsletter to hear about new free courses as they are released.

Every year, thousands of students decide to study with The Open University. With over 120 qualifications, we’ve got the right course for you.

Request an Open University prospectus