Friday, April 6, 2007

Lab 9

In lab 9 we did more data analysis. I learned more about the Sumation tool in excel. I learned how to calculate the slop of a line. I also learned how to calculate the y-intercept. We also learned how to calculate the correlation of the line. The main thing that I learned in lab 9 was how to use the data analysis tool. By going to the Tool drop-down, then to add-ins, you can have a new sheet with all calculations that deal with regression. This tool is very useful and saves lots of times.

The lab teaches us about linear regression. Fitting a line to points on a graph can be useful in data analysis. This is called a best-fit line. This line gives you three pieces of information. The slope, which lets you know how the line is increasing or decreasing. It also tells you about the y-intercept, which lets you know what the valuse of y is when x is zero. The last piece of information you can get with calulations of the best-fit line is the correlation of the line. This number is between 0 and 1. It is a percent of how close all of the points are to the best-fit line.

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