Answer:
the common ratio is either 2 or -2.
the sum of the first 7 terms is then either 765 or 255
Step-by-step explanation:
a geometric sequence or series of progression (these are the most common names for the same thing) means that every new term of the sequence is created by multiplying the previous term by a constant factor which is called the common ratio.
so,
a1
a2 = a1×f
a3 = a2×f = a1×f²
a4 = a3×f = a1×f³
the problem description here tells us
a3 = 4×a1
and from above we know a3 = a1×f².
so, f² = 4
and therefore the common ratio = f = 2 or -2 (we need to keep that in mind).
again, the problem description tells us
a2 + a4 = 30
a1×f + a1×f³ = 30
for f = 2
a1×2 + a1×2³ = 30
2a1 + 8a1 = 30
10a1 = 30
a1 = 3
for f = -2
a1×-2 + a1×(-2)³ = 30
-10a1 = 30
a1 = -3
the sum of the first n terms of a geometric sequence is
sn = a1×(1 - f^(n+1))/(1-f) for f <>1
so, for f = 2
s7 = 3×(1 - 2⁸)/(1-2) = 3×-255/-1 = 3×255 = 765
for f = -2
s7 = -3×(1 - (-2)⁸)/(1 - -2) = -3×(1-256)/3 = -3×-255/3 =
= -1×-255 = 255
2149 seats. Since 2149 rounds down to 2100 at the nearest hundred, this is the greatest amount of seats possible in the stadium. If there were 2150 seats, it would round to 2200 seats, so 2149 seats is the correct answer.
Hope this helps!
Answer:
A) Not statistical /this question is answered by counting the number of days in March. This produces a single number. This number is not answered by collecting data that vary.
B) Not Statistical/ this question is answered by a single number. It is not answered by collecting data that vary.
C) Statistical/ this question would be answered by all collecting data, and there would be variability in that data.
D) statistical/ this question would be answered by collecting data, and there would be variability in that data
E) Not Statistical/ this question is answered by a single response. It is not answered by collecting data that vary.
F) not statistical/ this question would be answered by counting the bricks. This produces a single number. This question is not answered by collecting data that very
G) non-statistical/ there is only one temperature
ANSWER:
STEP BY STEP EXPLANATION:
3.35 is bigger then 3.345
