How to convert trendline with E into Excel formula?

Copper Contributor

How to convert trendline with E into Excel formula?

How do I write this formula in an Excel cell? y = 4E-11x3 - 3E-07x2 + 0.001x

8 Replies

Re: How to convert trendline with E into Excel formula?

Perhaps you mean

``=4E-11*A1^3 - 3E-07*A1^2 + 0.001*A1``

Re: How to convert trendline with E into Excel formula?

I understand how to raise cell A1 to the exponent of 3 "A1^3"
What do I do with the 4E?

Re: How to convert trendline with E into Excel formula?

That's scientific notation for the number. 4E-11 is the same as 0.00000000004

Re: How to convert trendline with E into Excel formula?

Using the E as scientific notation does not work.

Here is my data

 CD14 Concentration (pg/mL) Average 2000 1.016 1000 0.706 500 0.440 250 0.255 125 0.140 62.5 0.101 0 0.000

y = 1E-10x3 - 6E-07x2 + 0.0012x

How can I write the slope formula so that I get reasonable values when solving unknows ie x?

Re: How to convert trendline with E into Excel formula?

Formula gives not exact but close to your data result

Please note, if you enter the formula with scientific notation Excel automatically converts such numbers to "number" format where possible.

For example, if you type

after you hit Enter same formula will be shown as

(in A1 is number 2).

Re: How to convert trendline with E into Excel formula?

Please let me rephrase my question. When I make a scatter plot graph with the above data, add a trend line I get the slope equation of "y = 1E-10x3 - 6E-07x2 + 0.0012x". How do I write this formula in a cell to solve for unknow x values? The response above has 0.8 and then the formula but does not give a result that should be 2,000.

Re: How to convert trendline with E into Excel formula?

Sorry, I'm missed - where is X and where is Y in your sample? Trendline formula shows how for known X calculate Y, not an opposite. Depends on that you may use any of formulas like

Re: How to convert trendline with E into Excel formula?

Highlight the formula on the graph and change the Number Category in the Format Trend Line Label from General to Number and set the Decimal Places to a high number such as 15. The equation should now become clearer. For example:
y = -5E-10x5 + 3E-07x4 - 5E-05x3 + 0.0054x2 - 0.2734x + 8.1635
is
y = -0.000000000502085x5 + 0.000000268770761x4 - 0.000054782577118x3 + 0.005380616863556x2 - 0.273384591163818x + 8.163540606805940
Which if x is in Cell L2 the Excel Equation is
= -0.000000000502085*L2^5 + 0.000000268770761*L2^4 - 0.000054782577118*L2^3 + 0.005380616863556*L2^2 - 0.273384591163818*L2 + 8.16354060680594