TI-83 / TI-84 Games and Programs

Given a probability distribution, the mean, variance, standard deviation, and coefficient of variance are found.

Find-Stats-From-Probability-Distribution Program Walkthrough:

1. 

   Enter the total number of values of a random variable and its corresponding probabilities. In simple terms, enter the total number of combinations possible of an event happening. Let’s say a coin is tossed four times. The total number of possible combinations is five: no heads, one head, two heads, three heads, or all four heads. Note that order of events does not matter. Also, this program works for any total number of values.

2. 

   The first event involves no heads. The probability of this happening is 1 out of 16. So, enter zero for X and 1/16 for PROB.

3. 

   The second event involves one head. The probability of this happening is 1 out of 4. So, enter one for X and 1/4 for PROB. Note that the recent values are displayed so that you don’t get lost in a long list of events.

4. 

   The third event involves two heads. The probability of this happening is 3 out of 8. So, enter two for X and 3/8 for PROB. Note that the recent values are displayed so that you don’t get lost in a long list of events.

5. 

   The fourth event involves three heads. The probability of this happening is 1 out of 4. So, enter three for X and 1/4 for PROB. Note that the recent values are displayed so that you don’t get lost in a long list of events.

6. 

   The fifth event involves four heads. The probability of this happening is 1 out of 16. So, enter four for X and 1/16 for PROB. Note that the recent values are displayed so that you don’t get lost in a long list of events.

7. 

   The mean, variance, standard deviation, and coefficient of variance are calculated. So if you did infinite sets of tossing a coin four times, two heads would be the average (mean) result, plus or minus one head (standard deviation). In this case, the variance equals the standard deviation.

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Give a set of indivdiual or grouped data values to find a large array of stat values: summation of X, summation of X^2, n, minimum X, maximum X, mean, median, range, midrange, variance, standard deviation, and coefficient of variance.

Find-Stats-From-Sample-Data Program Walkthrough #1:

1. 

   From a set of sample data values, choose individual or grouped. In this example, “individual values” is chosen.

2. 

   The number of values in the set is given here. In this case, there are five.

3. 

   Input the first individual value in the set.

4. 

   Input the second individual value in the set. Notice that the first value remains so that you don’t get lost in a potentially long list of values.

5. 

   Input the third individual value in the set. Notice that the previous values remain so that you don’t get lost in a potentially long list of values.

6. 

   Input the fourth individual value in the set. Notice that the previous values remain so that you don’t get lost in a potentially long list of values.

7. 

   Input the fifth individual value in the set. Notice that the previous values remain so that you don’t get lost in a potentially long list of values.

8. 

   From the given data values, the summation of X, summation of X^2, n, minimum X, and maximum X are calculated.

9. 

   From the given data values, the mean, median, range, midrange, variance, standard deviation, and coefficient of variance are calculated. Note that the previous screen gave the values necessary for showing work to get this set of stat values.

Find-Stats-From-Sample-Data Program Walkthrough #2:

1. 

   In this case, “grouped data” is chosen. Grouped data are sets of classes of data values. Let’s say that you interviewed 30 people from ages 18-45. Each one of them was married and had children. You wanted analyze marital status by age group, so you broke down the data into classes of 18-24, 25-31, 32-38, and 39-45.

2. 

   There are four age groups, or, in other words, there are four classes.

3. 

   Their responses were this: In the 18-24 group, there were five; in the 25-31 group, there were 13; in the 32-38 group, there were seven; in the 39-45 group, there were five. But to analyze this data, you must use the midpoint of each class and not the class limits.

4. 

   Input the midpoint of the class. In this case, you take 18 and 24 and divide them by two. Then, enter the frequency of the class. In this case, there were five people in the 18-24 age group that were married and had children.

5. 

   Input the midpoint of the class. In this case, you take 25 and 31 and divide them by two. Then, enter the frequency of the class. In this case, there were 13 people in the 25-31 age group that were married and had children. Notice that the previous values are displayed to prevent mistakes in entries.

6. 

   Input the midpoint of the class. In this case, you take 32 and 38 and divide them by two. Then, enter the frequency of the class. In this case, there were seven people in the 32-38 age group that were married and had children. Notice that the previous values are displayed to prevent mistakes in entries.

7. 

   Input the midpoint of the class. In this case, you take 39 and 45 and divide them by two. Then, enter the frequency of the class. In this case, there were five people in the 39-45 age group that were married and had children. Notice that the previous values are displayed to prevent mistakes in entries.

8. 

   From the given data values, the summation of X, summation of X^2, n, mean, variance, standard deviation, and coefficient of variance are calculated.

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