Understanding Probability Concepts

What does it mean if something is 'certain' to happen?

• It means it is guaranteed to happen.

• It means it might happen eventually.

• It means it is possible but not probable.

• It means it is unlikely to happen.

If an event is 'impossible', what is its probability?

• 0.25

• 1

• 0.5

• 0

Fill in the blank: The probability of an event that is 'likely' is between ___ and ___ .

• 0.3 and 0.7

• 0.1 and 0.9

• 0.0 and 0.5

• 0.5 and 1.0

What word describes an event that has a 50% chance of happening?

• equally likely

• certain

• improbable

• unlikely

If you say an event is 'unlikely', what does that mean about its probability?

• The probability is low, generally less than 50%.

• The probability is high, generally more than 75%.

• The probability is exactly 50%.

• The probability is certain, meaning it will definitely happen.

Fill in the blank: The probability of an event that is 'certain' is ___ .

• 1.5

• 0

• 1

• 0.5

What does 'random' mean in terms of probability?

• 'Random' means outcomes occur without a predictable pattern, each with a specific probability.

• 'Random' refers to outcomes that can be predicted with certainty.

• 'Random' indicates a fixed sequence of events.

• 'Random' means outcomes are always the same.

If an event has a probability of 0, what does that mean?

• The event has a 50% chance of occurring.

• The event will happen eventually.

• The event is highly likely to happen.

• The event cannot happen.

Fill in the blank: The probability scale ranges from ___ to ___ .

• 0 to 100

• 0 to 10

• -1 to 1

• 0 to 1

If you say an event is 'very likely', how would you express that on a probability scale?

• 0.2

• 0.5

• 0.9

• 0.8