1.3 ARITHMETIC MEANS

• Arithmetic means - This is the terms between the first and the last term.
• If a₁ is the first term and the last term is a₅, find the arithmetic means of the sequence.

  a2, a3, a4
• Find the arithmetic means of the sequence if the first term is a₁ and the last term is a₉

  a2, a3, a4, a5, a6, a7, a8
• Find the arithmetic means using the formula.

  If the first term is 5.

  The last term is 45.

  The common difference is 10.

  The number of terms are 5.

  5, 15, 25, 35, 45
• Find the common difference.

  If the first term is 7.

  If the last term is 61.

  If the number of terms are 7

  d = 9
• Find the common difference.

  If the first term is 598

  The last term is 166

  The number of terms are 13

  d = -36
• Find the number of terms

  If the common difference. is 986

  The first term is 59

  The last term is 15,835

  n = 17
• Find the first term if

  The common difference is -90,617

  The Last term is 1,171

  The number of terms are 10

  a₁ = 816,724