If y = 6.2 x = ?

Question

Finding the pressure drop (bar) of a pipeline, what time (min) will it take for the pressure to reach 6.2 bar?

x      y

0     8.58
5     8.40
10   8.25
15   8.12
20   8.02
25   7.91
30   7.82
35   7.74
40   7.65
45   7.59
50   7.50
55   7.43
60   7.39

Answer 1

You will need to find the quadratic regression formula for this one on your calculator.

 

First step: 

Go to STATS on your graphing calculator and select EDIT.

 

Second step: 

In the table, you will input all your x values in the first column, and all your y values in the second column correspondingly.

 

Be sure you table you clear before entering any data.

 

Third step:

Go the STATS, and select CALC.  From there, look for QUADREGRESSION.  Select it.

 

Fourth step:

Once you have your quadratic regression function, write it down on your paper.

 

Final step:

Plug in y=6.2 into your regression formula and solve for x.

 

To solve for x, use the quadratic formula.