Paulo uses an instrument called a densitometer to check that he has the correct ink colour. For this print job the acceptable range for the reading on the densitometer is 1.8 ± 10%. What is the acceptable range for the densitometer reading?

If the range of the answer should be + / - 10% of the particular value, then you have to solve for the percentage of that particular value. Since the value given is 1.8, we thus want to find 10% of that: 1.8 * 10/100 = 0.18 Then, add this value to the original value of 1.8: 1.8+0.18 = 1.98 Next, subtract. 18 from from the original value of 1.8: 1.8-0.18 = 1.62 The range will be between these two numbers, so the range is from 1.62 to 1.98.