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Logs: Data Lines
The results of an experiment are plotted on a graph of log10(y) against x, producing a straight line (not shown to scale) with gradient 1.3 and intercept –0.5.
The relationship between y and x is either y = p x q or y = p q x.
Fill in the values of the constants p and q to 3 dps and write x in the other input box to give the relationship between y and x:
y =
log10(y)
x

tickcross


Worked Solution:

The X–Y graph is a straight line
Y = m X + c with gradient m = 1.3 and intercept c = –0.5.
The Y values are the log10(y) values and the X values are the data x values.
The straight line in terms of the data values is
  log10(y) = 1.3 x –0.5
=>y = 101.3 x – 0.5
=>y = (101.3)x 10–0.5
=>y = 0.316 19.953x

© MEI Produced by Dr Ron Knott, revised 18 April 2008
tom . button [AT] mei . org . uk 		Test reference: LogsDataLines.html?ref=42538,qu=tox