A telecommunications engineer is modeling the signal strength, SSS microvolts, of a transmitter at a distance xxx km. A plot of log10S\log_{10} Slog10S against xxx produces a straight line lll.
The line lll passes through the points (0,3.42)(0, 3.42)(0,3.42) and (12,1.02)(12, 1.02)(12,1.02).
Write down an equation for lll.
Hence, or otherwise, express SSS in the form kbxkb^xkbx, giving the values of the constants kkk and bbb to 3 significant figures.
278 exam-style questions on CCEA A Level Maths 2.5 Data presentation and interpretation, covering 2.5.1 Data presentation and interpretation, 2.5.2 Data presentation and interpretation, 2.5.3 Data presentation and interpretation, 2.5.4 Data presentation and interpretation, 2.5.5 Data presentation and interpretation, 2.5.6 Data presentation and interpretation, 2.5.7 Data presentation and interpretation, 2.5.8 Data presentation and interpretation, 2.5.9 Data presentation and interpretation, and 2.5 Data presentation and interpretation. Each one has a worked solution and a mark scheme showing where the marks go.