The formula an = a1 + (n-1)d is used to find the ______ of a sequence

An expression denoting the sum of the terms of an arithmetic sequence is called __________.

Arithmetic mean between two terms is also known as ______________.

Who is the father of arithmetic progression

Insert four arithmetic means between -1 and 14

The 7th term of the arithmetic sequence 2, 4, 6, 8,... is 14.