# Changing incorrect maths definitions with the real one.

*label*Mathematics

*timer*Asked: Oct 29th, 2015

**Question description**

Given below are incorrect definitions of four key terms introduced in Book 1

Although wrong, each incorrect definition is written in the style used in the Glossary(glossary is below). Read the incorrect definitions and then answer the questions that follow.

Mean: The maximum value of a series of measurements (or numbers) divided by the number of those measurements.

Significant figures: The number of digits you quote when you write down the value of a quantity that has been measured with a degree of uncertainty. For example 10.2 cm is quoted to 3 significant figures and this means there may be some uncertainty in the final digit, but the other digits are certain. The smaller the number of significant figures quoted for a value, the smaller the uncertainty in that value.

Random uncertainty: A type of uncertainty derived from a measured quantity that is consistently higher or lower than a mean value i.e. many measurements being scattered all above or all below their mean value. The larger the random uncertainty associated with a measurement, the larger the scatter. Compare with experimental uncertainty, systematic uncertainty.

For each term: (i) Quote the correct definition as given in the Glossary. (ii) Clearly state the difference (or differences) that distinguish the correct definition from the incorrect one. (Guideline: one sentence for each definition)

**Glossary: **

**Mean: The sum of a series of measurements (or numbers) divided by the number of those measurements. **

**Significant figures: The number of digits you quote when you write down the value of a quantity that has been measured with a degree of uncertainty. For example, 10.2 cm is quoted to 3 significant figures and this means that there may be some uncertainty in the final digit, but the other digits are certain. The larger the number of significant figures quoted for a value, the smaller the uncertainty in that value.**

**Random uncertainty: A type of uncertainty derived from a measured quantity fluctuating about a mean value, i.e. Many measurements being scattered fairly randomly about a mean value.The larger the random uncertainty associated with a measurement, the larger the scatter. compare with experimental uncertainty, systematic uncertainty. **