This lesson teaches how to calculate mean, median, range, mode and probability. As a class, learners explore the differences in meaning among mean, range, median, and mode. Then working in teams, they use data from their workplace to compute values for these terms. Finally the class explores the term “probability” using a die.
Learner Needs & Goals:
Learning Activity Description:
1. Ask the participants what their average take home pay is per month. (Be sure to preface this question by stating that they are not to say this aloud.) Ask them how they calculated this. Was it by adding up their take home pay for each month and then dividing it by the number of months in the year? Tell the class that the word mean is often used instead of average. Explain that average or mean is the resulting value from adding a group of numbers together and dividing the sum by the number of items in the group. Demonstrate the concept by working through several sample problems on the board. Ask individuals how old they think the President of the United States is. Show them how to calculate the average age that individuals have guessed.
2. Ask if anyone can explain the term range. Point out that the range is the difference between the greatest and the smallest value (number) in a group. Use the numbers from the previous exercise to demonstrate.
3. Show the class a picture of a divided highway and ask the participants to define what the strip of grass between the two sides of the highway is called - a median. Lead the participants to discuss the similarities between the two sides of the highway, for example, there are two lanes on each side of the median. Explain that the median is the number at which half the values in a sample fall above and half fall below. It may or may not be the same as the mean or average. To demonstrate how to find the median, list all the numbers in a population (a group of very similar or like items) from the highest value to the lowest, and the middle number is the median or midpoint. If there is an even number of values, use the average of the two middle numbers for the midpoint or median.
4. Next, explain that mode is the most frequently used number in a sample population. For example, in the list: 11; 12; 45; 23; 24; 23, the 23 is the mode. It is the most frequently occurring value or number.
5. Have the participants compute the mean, range, median, and mode for a fictitious employee’s earnings for the past six months. Have participants check their answers as you read the correct answers.
6. Divide the class in teams according to the color of the dots placed on the backs of their chairs. The teams should assign the following roles to group members: recorder, reporter, facilitator, and timekeeper. Together the teams find the answers to a handout that lists several work-related problems.
7. Ask the teams to go into the facility and collect the assigned information from which they will figure the mean, range, median, and mode. Some possible assignments may be employee hair color, age, or birth month. List twice the number of choices as the number of teams. Have each team select one problem.
8. The teams should return to the classroom and prepare their information for reporting. If the class has completed the lesson on graphs, learners may choose to use graphs to present the information during the reporting period. Have the teams report their findings.
9. Introduce probability by rolling a die and asking the learners what the chances are of rolling a snake eye (one) on the next roll. Explain that probability is the likelihood of an event occurring. Point out that this is important for quality control in a manufacturing plant. It is an important part of statistical information.
10. Ask what the chances are of rolling an odd number? An even number? Explain that there are six sides to a die and that each side is equally likely to be turned up after the die is thrown. The probability that the side with one dot lands up is 1 in 6 or 1/6. Write the formula that goes along with figuring probability on the board.
P = number of favorable ways11. Explain that the secret to using a formula is to replace the words with the numbers meaning the same thing. The line between the numbers means to divide. Have participants practice by rolling die and completing some sample problems.
total number of ways
Materials and Resources:
Because the business used these principles to report the producton of each machine and part, the participants were able to use the skills learned in class the very next day. __________________________________________________________