Introductory

Also known as an average, the mean can be used to represent the "best overall" value from your data by considering all of the values present. In the real world, known constants (like gravity) are often represented as the average of the values measured for them. 

Means can be found by adding up all the data values and dividing by the number of values. Here is an example

Data values: 3, 8,12, 7

Mean = (3+8+12+7)/4

Mean = 7.5

Most often, the mean of every group with the same treatment is found to determine the trend!

The median is the middle value of all the data points. To find the median, put all the numbers in order from lowest to highest and pick the middle number. 

Median is often used when there is an outlier in the data. An outlier is a data value that is very different from the other data values and is usually due to experimental error.

• If there is an odd number of data values, there is just one value

• If there is an even number of data values, pick the two middle numbers, add them, and divide by two

Here is an example!

Data values: 3, 8,12, 7

1. Place them in order from least to greatest - 3, 7, 8, 12

2. Pick the middle number(s) - 3, 7, 8, 12

3. Find the average of the middle numbers -  (7+8)/2 = 7.5

Here are some reminders when making a graph to represent your data visually!

• Add a title

  • Some sample titles

    • The dependence of [dependent variable] on [independent variable]

    • [Dependent variable] as a function of [independent variable]

• Label the x- and y-axes of the plot

• Include units in your titles

• Use contrasting colors

• Add trendlines/lines of best fit to scatter plots 

• Adjust your scales

  • Example: If the smallest data point on an axis x = 100, the smallest value on that axis should not be 0

Choose what type of graph to use depending on your data. Check out the resource below to help you determine what type of graph to use!

• Bar graphs

• Pie charts

• Histograms

• Scatterplots/dot graphs