AI generatedProbabilityKey Stage 3

Using the probability scale

Using the probability scale.

  • Probability = favourable outcomes ÷ all outcomes when individual outcomes are equally likely.
  • A probability lies between 0 and 1; complementary probabilities sum to 1.
  • Experimental relative frequency estimates probability and can vary between samples.

Example 1

Read P on the probability scale and describe the likelihood.

Probability scaleP
P = 0; impossible.

Probabilities run from 0 to 1 inclusive. A probability of means an even chance.

Example 2

Read P on the probability scale and describe the likelihood.

Probability scaleP
P = ; unlikely.

Probabilities run from 0 to 1 inclusive. A probability of means an even chance.

Your turn

Question 1

Read P on the probability scale and describe the likelihood.

Probability scaleP
Check answer
P = ; even chance.

Probabilities run from 0 to 1 inclusive. A probability of means an even chance.

Question 2

Read P on the probability scale and describe the likelihood.

Probability scaleP
Check answer
P = ; likely.

Probabilities run from 0 to 1 inclusive. A probability of means an even chance.

Question 3

Read P on the probability scale and describe the likelihood.

Probability scaleP
Check answer
P = 1; certain.

Probabilities run from 0 to 1 inclusive. A probability of means an even chance.

Question 4

Read P on the probability scale and describe the likelihood.

Probability scaleP
Check answer
P = 0; impossible.

Probabilities run from 0 to 1 inclusive. A probability of means an even chance.

Question 5

Read P on the probability scale and describe the likelihood.

Probability scaleP
Check answer
P = ; unlikely.

Probabilities run from 0 to 1 inclusive. A probability of means an even chance.