# Question regarding cross-linear interpolation

#### mattskie

This is not a homework problem.

I am given the equation of two lines at different temperature gradients for (suction line temp,suction line pressure) => (x,y)
At outdoor temp 95*F; y=.41667x+54.1667
At outdoor temp 85*F; y=.4231x+50.3846

I need to find suction line pressure for 72*F temp (72,y) at 92*F outdoor temp

I believe the method is cross linear interpolation, how do i do this??

Methodology needed, i can handle the calculations. This was the closest I've found to a method, but the notation is confusing and I can't get it to work: http://www.mathpages.com/home/kmath323/kmath323.htm

#### mathman

I believe this means interpolating the x coefficient and the constant separately to get the equation for 92°F.

I did not check the reference.

Last edited:

### Physics Forums Values

We Value Quality
• Topics based on mainstream science
• Proper English grammar and spelling
We Value Civility
• Positive and compassionate attitudes
• Patience while debating
We Value Productivity
• Disciplined to remain on-topic
• Recognition of own weaknesses
• Solo and co-op problem solving