how can graphs help us summarize our data?

Answer 1

By putting all data into one neat picture- be it a line graph, pie chart, a cumulative frequency polygon or a stem and leaf chart.

Think for instance if you have data in the thousands or even tens of thousands or millions, there will not be even enough space to write them all down in one paper. Can you imagine the finger and wrist cramps of just writing or typing them down.

Worse, you are asked to SORT a million data points. It will be next to impossible. Graphing calculators can easily sort and graph these million points that can easily fit an 8 x10 paper.

These graphs show trends, like going down or sales going up without seeing the individual points. Or, in a pie chart, how of you salary goes to TAXES, so that you alarm Congress that there is nothing left to even buy food. Or, graphs can show the trends in the use of blogs vs. email vs. snailmail, etc. Or, to compare the number of hits between 2 competing teen rave aprty sites. ETc, etc.

Answer 2

easy...use numerical data. domain (x) being changing variable data, and range being controlled variable data. Depending on the relationship the data is summarized. for example, if a car goes faster as time goes on, (acceleration) on a speed vs. time graph it will show a upward curve. and if you need to put where it is constant you put a horizontal line. if you need to put where it decelerates you put a down ward curve, etc. Good luck.