Question

What does a plus over a minus sign mean? I'm a science student and am doing some data analysis for one of my reports. Am not great on maths and don't know what a plus sign with a minus sign under it means. Can anyone help? Thankyou (am doing mean volume and standard deviation calculations - don't know if it makes a difference)

Answer 1

Plus over minus has multiple meaning, it generally indicates a choice of exactly two possible values one of which is the negation of the other.

Answer 2

that symbol represents "plus out minus". usually represents uncertainty if it is beside a number.

e.g. 3± 0.3 means that the actual answer lies between 2.7 and 3.3