How much did YOU spend?

There were 21 students in class who each wrote, on a piece of paper, how much they spent on their textbooks for the fall 2012 semester at Mesa Community College. The image below shows the amounts they spent.

With all that information, we had to input it into a TI-73 calculator. I had to interpret the mean, the smallest amount paid, the median, the standard deviation, and the mode. Before I found any of the information need, I had to look up what standard deviation meant. Standard Deviations are the SQUARE ROOT of the arithmetic average of the squared differences between each number and the mean of the collection of numbers. 

    I still don't understand what the means. When I added up the amount of money each student spent on textbooks, it was $6,129 for twenty-one students. 

      - The mean was 291.86; the average amount of money spent on textbooks was $291.86.

      - The smallest amount paid was 40; the least amount of money spent on textbooks was $40.00.

      - The median was 225; the middle price was $255.00.

      - The standard deviation was 174.21, most students spent between $117.00 and $465.00 for textbooks.

      - The mode was (200, 250)

Introduction to Statistics.....With Calculators

      I never really understood statistics at all. So I usually do what I do best so I can better understand it; looking up the definition. Statistics is the practice or science of collecting and analyzing numerical data in large quantities. What I didn't know was that I was working with statistics all this time. Doing the Class Data, Stem & Leaf plot, histogram and other graphs all associate with statistics. 

      When you use a TI-73 calculator or other similar calculators, the symbols listed above tell you what each means. This project we did in class was sort of simple. We worked on inputting information into the calculator to find the mode of the test score a class earned. 

      - There were 15 scores that a class earned (71, 98, 93, 42, 78, 82, 100, 91, 83, 85, 71, 73, 64, 68, and 55)

        - The mode for the test data set was 71. A better answer would be there were more students who scored a 71 on their test. 

The project was helpful in so many ways, but I think I still don't understand it.

Grab A Hand Full of Cubes

      When class started, our instructor informed that class that we were going to be working on Mode, Median and Mean of data. I felt intimidated; I have always avoided working with the three subjects. Someone would explain to me so many times what each means, but I have always forgotten. I always referred to a textbook about the definition to remind me. 

      - Mode is a list of numbers that occurs most frequently. There can be more than one mode, for example two numbers can occur more frequently.

      - Median is the "middle" or "halfway" point in a list of numbers that is arranged in increasing (or decreasing) order. 

      - Mean is the most useful, it’s the measure of central tendency, or in other words it’s the arithmetic average. 

      I felt like the little project we did in class was very helpful. Each student had to grab a handful of cubes from a box that the instructor walked around the classroom with. I grabbed 13 cubes. I was surprised because I have small hands. There were 22 students who participated. Six students grabbed 8 cubes, one student grabbed 9 cubes, two student’s grabbed 10 cubes, four students grabbed 11, four students grabbed 12, and five students grabbed 13(me being one of them). There was a total of 234 cubed drawn from the box. With the worksheet, we had to find out the Mode, Median, and the Mean. As we were working, the instructor was explaining to us about how to find each. 

      It was so much fun doing this project. I am a slow learner, but doing hands on activity helps me learn more. 

The Class Data and Our Height

I have always enjoyed working with math. Working with numbers and graphs has always been interesting to me. My math class all wrote our height in inches on her white board. There were 22 students all from 60 inches to 72 inches. 

As the instructor was talking to the class about data, I was amazed to find out that I am the shortest student in the class. The instructor explained that we were going to put our class data on a Stem & Leaf Plot. I have always thought Stem & Leaf plots were easy to work with. On a Stem & Leaf Plot, they are used to organize the data. 

After the stem & leaf plot, the instructor showed us students how to find the frequency of the Height of Class in inches. She drew a chart (as shown below) on the white board and explained to us the importance of getting the information correct. For the frequency in the class; nine students were in the height from 60-64 inches, ten students were in the height from 65-69 inches and three students were in the height from 70-74 inches.

I always felt that graphs were fun to work with. I have always had fun constructing graphs, but it wasn't until recently that I have been introduced to a Histogram graph. When constructing a graph you must always have a title for the graph and both sides of the graph must be labeled. From the frequency chart (as shown above) the instructor showed the class how to construct a Histogram. We used the Frequency and interval (but labeled as Height in inches) for the graph.

It was a lot of fun working with the class data during this class session.