Question

Need help with sigma notation

Answer 1

Answer:

• 114126  

Step-by-step explanation:

The given expression describes the GP with

The first term:

• t = 80(1.23²⁻²) = 80(1.23⁰) = 80

The common ratio:

• r = 1.23

It is required to find the sum of the terms from 2 (the bottom number of sigma) through 29 (the top number of sigma)

The number of terms is

• n = 29 - 2 + 1 = 28

The sum of the first 28 terms is

• Sₙ = t(rⁿ - 1)/(r - 1)
• S₂₈ = 80(1.23²⁸ - 1)/(1.23 - 1) = 114125.75573 ≈ 114126 (rounded)