Answer:
Common ratio = 2
Explanation:
The formula for nth term of a geometric progression is given as:
aₙ = arⁿ⁻¹
Given the following values
First term a = 7
r = unknown
n = unknown
Last term = nth term = aₙ = 448
Sum of the terms = 889
Substituting
448 = 7rⁿ⁻¹
Divide both sides by 7
rⁿ⁻¹ = 448/7
rⁿ⁻¹ = 64
Converting 64 to a power
rⁿ⁻¹ = 2⁶
Equating the powers together,
n - 1 = 6
n = 6+1 = 7
Number of terms (n) = 7
Therefore, the common ratio of the geometric progression( r ) = 2
