6.1. Surveys and Sampling http://www.ck12.org
on the homescreen and then press[STO], enter the rand function, and press[ENTER]. As long as the number you
chose to seed the function is different, you will get different results.
Now, back to our example, if we want to choose a student, at random, between 1 and 25, we need to generate a
random integer between 1 and 25. To do this, press[MATH],[PRB], and choose the random integer function.
The syntax for this command is as follows:
RandInt( starting value, ending value, number of random integers)
The default for the last field is 1, so if you only need a single random digit, you can enter:
In this example, the student chosen would be student #7. If we wanted to choose 5 students at random, we could
enter:
However, because the probabilities of any digit being chosen each time are independent, it is possible to choose the
same student twice.
What we can do in this case is ignore any repeated digits. Student 10 has already been chosen, so we will ignore
the second 10. Press[ENTER]again to generate 5 new random numbers and choose the first one that is not in your
original set.
In this example, student 4 was also already chosen, so we would select #14 as our fifth student.