Anonymous

# Soo urgent! Which one is more reliable and acceptable? Interpolation or extrapolation? Explain.?

Explain how both can be achieved using the line of best fit?

(These are questions from my chemistry pre-lab)

Relevance
• Anonymous

Interpolation ('inter" = between) is more reliable because you're estimating a data point that is between two known data points. The answer you're estimating is within the range that you already have measured, i.e., "known," values for. Extrapolation estimates a data point outside the measured range where new trends could occur - extrapolation assumes that the same trend within the known range continues outside of the range. This assumption is not necessary with interpolation.

Hope this helps.

Source(s): BS Chemistry
• Amy F
Lv 5

Once you've got a best-fit line, with an equation, you can guess what value of your dependent variable you might get for a given value of the independent variable. For instance, once you've calculated the amount of light absorbed by different concentrations of a colored solution, you can use the equation you find and plug in concentrations you've never tested to see how much light they'd absorb. Even if you make a graph by hand without an equation, you can still kind of trace a line up from the concentration you want and find what level of absorbency it intersects the graph at. This is called either extrapolation or interpolation.

The difference between interpolation and extrapolation is that interpolation is using a best-fit line to find values within the range of your measured values, and extrapolation is using the best-fit line to find values outside that range. In my previous example, if I used concentrations of 1, 0.1 and 0.01 M to make my line, I would interpolate a value for 0.05, but I would extrapolate a value for 0.005, because it's lower than any of my measurements. Interpolation is more reliable, because outside the bounds of your experiment you have no guarantee that the graph continues in a straight line (or regular curve or whatever it is where you drew it).

If you're having trouble remembering which is which, remember that extra- means outside (like an extramarital affair) and inter- means between (like an interstate highway).