A lot of scientific data, particularly in the fields of biology and chemistry, describe much larger quantities. Showing all of that data on a chart can be difficult using standard axis settings. In this video, learn how to use logarithmic values to fit yo
- [Instructor] Most business data describes dollar amounts in the hundreds, thousands, or hundreds of thousands of dollars. A lot of scientific data, particularly in the fields of biology and chemistry, describe much larger quantities. Showing all of that data on a chart can be difficult using standard axis settings, so in this movie, I will show you how to use logarithmic values to fit your data into a readable chart. My sample file is LogarithmicScale, and that's an Excel workbook you can find in the chapter two folder of your exercise files collection.
The data that I have here in cells B6 through B11 is expressed in scientific notation. Scientific notation has a base number. In cell B6, that is 2.93, and then it is multiplied by 10 to the power, in this case, of four. So that's what 2.93 times E plus 04 means. If you look at the value for cell B6 on the formula bar, you can see that it is actually 29,250. So it's just another way of saying that we have 2.93 times 10,000 or 10 to the fourth power.
And you can see that the numbers go up quite significantly from there. The next value in cell B7 is 9.76 times 10 to the eighth. So that's a number that is 1000 times larger than the number in B2, and the next number in cell B8, 1.45 times E to the 13th, or 10 to the 13th, is 10,000 times larger than the value in cell B7. So you can see that values get very quickly when you are dealing in powers of 10.
The graph, even though we're dealing with large values, you can see that the value in cell B11, which is 9.02 times 10 to the 15th, overwhelms all of the other values, and the vertical axis goes from zero immediately up to one times E to the 15th, so that is 10 to the 15th power or one followed by 15 zeroes, and that, as you can see, is an extremely large number. So rather than use a scale where only the largest value has any sort of meaningful indication within the chart, we can change the vertical axis to use a logarithmic scale.
To do that, right click any value on the vertical axis and then click Format Axis. In the Format Axis dialog box under Axis Options, scroll down, and you can see that there is a Logarithmic Scale check box. Go ahead and select that. And we'll leave the base at 10 because we're dealing with powers of 10 for scientific values, and you can see that the chart has changed. The values on the vertical axis are separated by two powers of 10, so 100 times.
So that means that a value that is, say, one times E to the eighth, or 10 to the eighth, is 100 times larger than a value at one times E to the sixth, or 10 to the sixth. When you work with scientific data, this sort of logarithmic scale allows you to compare values more meaningfully than a chart that just has its largest value overwhelming all the others.
- Distinguish between the mean, median, and mode.
- Describe the relationship between variance and standard deviation.
- Identify a nondirectional hypothesis.
- Point out the difference between COVARIANCE.P and COVARIANCE.S.
- Explain correlation.
- Analyze Bayes’ rule.