Find the sum of the first 8 terms of the following sequence. Round to the nearest hundredth if necessary.100,88,77.44,…Sum of a finite geometric series:Sn=1−ra1−a1rnAnswer:
Q. Find the sum of the first 8 terms of the following sequence. Round to the nearest hundredth if necessary.100,88,77.44,…Sum of a finite geometric series:Sn=1−ra1−a1rnAnswer:
Identify common ratio: First, we need to identify the common ratio r of the geometric sequence. We can find this by dividing the second term by the first term.r=10088=0.88
Use sum formula: Next, we use the formula for the sum of the first n terms of a geometric series: Sn=1−ra1−a1⋅rn where Sn is the sum of the first n terms, a1 is the first term, r is the common ratio, and n is the number of terms.
Plug in values: We plug in the values we know into the formula: S8=(1−0.88)(100−100×0.888)
Calculate the sum: Now we calculate the sum using the values:S8=1−0.88100−100×0.888S8=0.12100−100×0.23357214690901212S8=0.12100−23.357214690901212S8=0.1276.64278530909879S8=638.6898775758232
Round the sum: Finally, we round the sum to the nearest hundredth: S8≈638.69