Quantity is used to describe the amount in the parentheses because the value of x. The mean is the usual average so Ill add up and then divide. In algebra an equation can be defined as a mathematical statement consisting of an equal symbol between two algebraic expressions that have the same value.
What is on the left x 2 is equal to what is on the right 6 So an equation is like a statement this equals that.
Similarly the mean of a sample x 1 x 2 x n displaystyle x_1x_2ldots x_n usually denoted by x displaystyle bar x 1 is the sum of the sampled values divided by the number of items in the sample. When you know the value of one quantity you can find the value of the other using the formula. It will have an equals sign like this. An equation says that two things are equal.