I have data that look like this, with a tonnage measure and density measure for each carriage in a bunch of trains.

Train Carriage_No Tonnes  Density
A     1           105.5   2.12
A     2           104.9   2.28
A     3           101.2   2.30
A     4           108.7   2.41
B     1           112.3   2.51
B     2           109.7   2.34

etc..

How do I determine density's contribution to the variation in tonnes? What is doing this called? Some R code would be most helpful!

Our goal is to fit more tonnes into each carriage, but the variation around the mean is such that we're overloading an unacceptable percentage of carriages. Therefore we need to tighten the variation to allow us to increase the mean (i.e. more total tonnes) without overloading.

There are a few things we can do to improve tonnage variability, but controlling density isn't one of them. But reacting to changes in denisty may be something we can do. I'd like to understand how much the density accounts for the variation in tonnes so that we know the remaing portion of the variation in tonnes that we can affect.

I have data that look like this, with a tonnage measure and density measure for each carriage in a bunch of trains.

Train Carriage_No Tonnes  Density
A     1           105.5   2.12
A     2           104.9   2.28
A     3           101.2   2.30
A     4           108.7   2.41
B     1           112.3   2.51
B     2           109.7   2.34

etc..

How do I determine density's contribution to the variation in tonnes? What is doing this called? Some R code would be most helpful!

Our goal is to fit more tonnes into each carriage, but the variation around the mean is such that we're overloading an unacceptable percentage of carriages. Therefore we need to tighten the variation to allow us to increase the mean (i.e. more total tonnes) without overloading.

There are a few things we can do to improve tonnage variability, but controlling density isn't one of them (reacting to changes in density may be possible). So I'd like to understand how much the density accounts for the variation in tonnes.

I have data that look like this, with a tonnage measure and density measure for each carriage in a bunch of trains.

Train Carriage_No Tonnes  Density
A     1           105.5   2.12
A     2           104.9   2.28
A     3           101.2   2.30
A     4           108.7   2.41
B     1           112.3   2.51
B     2           109.7   2.34

etc..

How do I determine density's contribution to the variation in tonnes? What is doing this called? Some R code would be most helpful!

Our goal is to fit more tonnes into each carriage, but the variation around the mean is such that we're overloading an unacceptable percentage of carriages. Therefore we need to tighten the variation to allow us to increase the mean (i.e. more total tonnes) without overloading.

There are a few things we can do to improve tonnage variability, but controlling density isn't one of them. I'd like to understand how much the density accounts for the variation in tonnes so that we know the remaing portion of the variation in tonnes that we can affect.

I have data that look like this, with a tonnage measure and density measure for each carriage in a bunch of trains.

Train Carriage_No Tonnes  Density
A     1           105.5   2.12
A     2           104.9   2.28
A     3           101.2   2.30
A     4           108.7   2.41
B     1           112.3   2.51
B     2           109.7   2.34

etc..

How do I determine density's contribution to the variation in tonnes? What is doing this called? Some R code would be most helpful!

Our goal is to fit more tonnes into each carriage, but the variation around the mean is such that we're overloading an unacceptable percentage of carriages. Therefore we need to tighten the variation to allow us to increase the mean (i.e. more total tonnes) without overloading.

There are a few things we can do to improve tonnage variability, but controlling density isn't one of them. But reacting to changes in denisty may be something we can do. I'd like to understand how much the density accounts for the variation in tonnes so that we know the remaing portion of the variation in tonnes that we can affect.