Question

A car speedometer has a 3% uncertainty. What is the range of possible speeds (in km/h) when it reads 120 km/h

Answer 1

The range of possible real speeds is:

`x\ -\ the\ actual\ speed \\116.4 < x < 123.6`

Step-by-step explanation:

If we know that the certainty of a measurement is 3% - we refer that to the measured value - we calculate how much is 3% of 120:

`120 * 3\% = 3.6`

To calculate the lower limit - we subtract the given value from the measurement value and to calculate the upper limit - we have to add.