Finding Probabilities

Practise how to calculate probabilities when each outcome is equally likely.



But what is the probability that when you look out of a window at a street, the next car that passes will be red?

You need to use relative frequency

Finally, watch this video

Probability

Here, there are some execises about how to calculate the probability of chance events. Try to express the results as a fraction, as a decimal number and as a percentage too. Certain and Impossible Events

Sometimes, there is a small problem in listing all the outcomes of an experiment; practise it in this page Sample spaces

Two problems

1. The average weight of the 11 players in a football team was 72.5 kg. The average weight of the 5 reserve players was 75.6 kg. What was the average weight of the whole squad? ( Give your answer to 3 s.f.)

2. The mean daily weight of potatoes sold in a greengrocer's from Monday to Friday was 14 kg. The mean daily weight of potatoes sold from Monday to Saturday was 15 kg. How many kg of potatoes were sold on Saturday?

Careful with this, the mean is useful to work out the total weight.