i dont know how to match a function with stats i have.

[red_radishs]

Hello, I am a 10th grader. We did a lab in science. and i received coordinates which our math teacher decided to create a homework with. He wants us to find the function corresponding to these coordinates. I have tried all, I did some research, l but nothing at all helped me.

 

[MarkFL]

What was the topic of the lab?

 

[red_radishs]

What was the topic of the lab?

We created some solutions with several concentrations ranging from 1% to 20% concentrations and measured their absorbance using a spectrophotometer.

 

[BigBeachBanana]

Hello, I am a 10th grader. We did a lab in science. and i received coordinates which our math teacher decided to create a homework with. He wants us to find the function corresponding to these coordinates. I have tried all, I did some research, l but nothing at all helped me.View attachment 35097

It looks like a logarithmic function. A common one is: [imath]y= a\ln(x) + b[/imath]
Can you use the known points to find the values of [imath]a \text { and } b?[/imath]

Note that you might not find one that perfectly fits the values but it should be with high accuracy.

 

[Dr.Peterson]

Hello, I am a 10th grader. We did a lab in science. and i received coordinates which our math teacher decided to create a homework with. He wants us to find the function corresponding to these coordinates. I have tried all, I did some research, l but nothing at all helped me.View attachment 35097

Hopefully what he meant was "find a function". It will not be unique, but will depend on what type of function you try.

Try a function of the form y=a*b^x+c, or y=a*e^(bx)+c. You could also use a polynomial (a cubic, say), but that will look quite different. (I also tried a log, but that didn't work well at all.)

Desmos can do this for you; look for "regressions" in their documentation.

 

[red_radishs]

Hopefully what he meant was "find a function". It will not be unique, but will depend on what type of function you try.

Try a function of the form y=a*b^x+c, or y=a*e^(bx)+c. You could also use a polynomial (a cubic, say), but that will look quite different. (I also tried a log, but that didn't work well at all.)

Desmos can do this for you; look for "regressions" in their documentation.

thank you

 

[red_radishs]

It looks like a logarithmic function. A common one is: [imath]y= a\ln(x) + b[/imath]
Can you use the known points to find the values of [imath]a \text { and } b?[/imath]

Note that you might not find one that perfectly fits the values but it should be with high accuracy.

Thank you too

 

[Harry_the_cat]

Do you know how to do a scatterplot on Excel?

 

[Dr.Peterson]

Here are my results:

​

Green is the exponential y=a*e^(bx)+c, red is the cubic y=ax^3+bx^2+xcx+d, and blue is the log y=a log(x+b)+c, which doesn't actually pass through the points.

The exponential clearly seems most appropriate (and gives an exact fit despite having only 3 parameters for 4 points); but whether it's actually suitable for the actual experiment depends on the nature of the experiment.