# Calculate the average speed from a bar graph

1. Oct 4, 2007

### Jath

Well I need to calculate the average speed from a bar graph and I do believe it said percent difference, then find the percent difference from the bar graph to my line graph. All I have is pictures of the bar graph, so can someone please tell me how to find the average speed and the percent difference? If you can thanks a lot. Sorry for the crappy pictures too.

http://s3.photobucket.com/albums/y71/Jath/?action=view&current=Physics1.jpg
http://s3.photobucket.com/albums/y71/Jath/?action=view&current=Physics2.jpg

2. Oct 5, 2007

### Astronuc

Staff Emeritus
It's difficult to understand the two graphs. There are 8 bars in one and 6 in the other. Do they represent the same time intervals, such that each bar has equal weight.

Assuming one has N quantities vi, then how does one determine the average value?

Then with the average value, take each vi, subtract the average, which will give the difference between the particular value and the average. How would one then determine the percent difference?