Chapter 2, Problem 2.37P

Interpretation Introduction

(a)

Interpretation:

The value of vapor pressure at T = 185 °C should be determined by using two-point linear interpolation.

Concept introduction:

Linear interpolation equation,
If the two known values are (x₁ , y₁ ) and (x₂ , y₂ ), then the y value for some point x is,

$y=y_1+\left(x-x_1\right)\frac{y_2-y_1}{x_2-x_1}$

Interpretation Introduction

(b)

Interpretation:

The vapor pressure at 148.2 °C and the percentage error considering given value should be determined along with the reason for expecting the error which is associated with part (a) to be significantly less than part (b).

Concept introduction:

Linear interpolation equation,

If the two known values are (x1, y1) and (x2, y2), then the y value for some point x is,

$y=y_1+\left(x-x_1\right)\frac{y_2-y_1}{x_2-x_1}$

The formula to calculate percentage error is,

$\text{Percentage}\text{error}\text{=}\frac{\text{Calculated}\text{value}\text{-}\text{Actual}\text{value}}{\text{Actual}\text{value}}\text{×}\text{100\%}$