Name________________________

THEORETICAL PROBABILITY #1--KEY

Directions:  Theoretical probability describes how likely it is that an event will happen.  Use the probability chart below to decide whether each event below is impossible, unlikely, equally likely, likely, or certain to happen.

0                            ¼                            ½                            ¾                            1

|_______________|_______________|_______________|_______________|

Impossible               unlikely                  equally                   likely                      certain

likely

Example:  A two sided coin is flipped and lands on tails.                                            ½ --Equally likely

EVENT                                                                                                                              PROBABILITY

1)  A two-sided coin is flipped and lands on heads.                                                             ½ -- equally likely___

2)  Roll a die and get a number greater than six.                                                                  0 – impossible      ___

3)  Spin a spinner numbered 1-8, and you land on a number less than 3.                            ¼  – unlikely        ___

4)  You will watch TV today.                                                                                              1  -- certain              __

5)  Pick a blue marble from an equal number of blue, yellow, red, and green marbles.     ¼  – unlikely        ___

6)  You will have fish for dinner tonight.                                                                             ¼  – unlikely ??? ___

7)  Pick an ace from a regular deck of cards.                                                                       ¼  – unlikely        ___

8)  Pick a red card from a regular deck of cards.                                                                  ½ -- equally likely___

9)  Your class will go on a field trip this year.                                                                     ¾  -- likely              __

10)  Roll a die and get an even number.                                                                               ½ -- equally likely___

11)  Roll a die and get a number that is a factor of 30                                                         ¾  -- likely              __

12)  It will snow in your town tonight.                                                                                 ¼  – unlikely  ???___

13)  Your birthday will fall on a Friday this year.                                                                ¼  – unlikely        ___

14)  Pick a purple marble out of a bag of red marbles.                                                         0 – impossible      ___

15)  Picking a vowel from the letters in your school’s name.                                              ¼  – unlikely  ???___