Using Probability to Predict

Front

What is probability?

Back

Probability is a measure of how likely an event is to occur, expressed as a number between 0 and 1.

Front

What is the probability of rolling a number less than or equal to 5 on a standard die?

Back

The probability is 5/6, since there are 5 favorable outcomes (1, 2, 3, 4, 5) out of 6 possible outcomes.

Front

If a die is rolled 90 times, how many times would you expect to roll a number less than or equal to 5?

Back

You would expect to roll a number less than or equal to 5 approximately 75 times.

Front

What does P(not A) represent in probability?

Back

P(not A) represents the probability that event A does not occur.

Front

If the probability of event A is 1/4, what is P(not A)?

Back

P(not A) = 1 - P(A) = 1 - 1/4 = 3/4.

Front

How do you set up a proportion to predict outcomes?

Back

To set up a proportion, compare the ratio of favorable outcomes to total outcomes in a sample to the ratio of predicted outcomes to total predictions.

Front

If 100 students chose animals and 60 chose giraffes, what is the probability of choosing a giraffe?

Back

The probability is 60/100 or 3/5.

Front

If 250 students are asked to choose an animal, how many would you predict would choose a giraffe based on previous data?

Back

You would predict 150 students would choose a giraffe (using the ratio 60/100).

Front

What is the probability of choosing a letter other than 'A' from the word 'ALGEBRA'?

Back

The probability is 5/7, since there are 5 letters that are not 'A' out of 7 total letters.

Front

If I spin a spinner 35 times and land on yellow 1/5 of the time, how many times would I expect to land on yellow?

Back

You would expect to land on yellow approximately 7 times.