The nth term of the geometric sequence is:
an=ar^(n-1)
where
a=first term
r=common ratio
n=nth term
from the question:
120=ar(3-1)
120=ar^2
a=120/(r^2)....i
also:
76.8=ar^(5-1)
76.8=ar^4
a=76.8/r^4.....i
thus from i and ii
120/r^2=76.8/r^4
from above we can have:
120=76.8/r²
120r²=76.8
r²=76.8/120
r²=0.64
r=√0.64
r=0.8
hence:
a=120/(0.64)=187.5
therefore the formula for the series will be:
an=187.5r^0.8
Answer:
and 
Step-by-step explanation:
Given
5 daises to 2 roses
Required
Determine the relationship between them
The question shows a direct proportion between number of daises and roses.
i.e.
Where d = daises and r = roses
Convert the above expression to an equation
Make k the subject
When d = 5 and r = 2;
So, the first relationship between d and r can be gotten by substituting 2.5 for k in d = kr
So:
----------- (1)
Make r the subject in (1)
------------------------(2)
Hence, the relationships between d and r are:
and
Why did the person above me say ok for an answer
We can use ratios here. The real size would have to be proportional, meaning that if I increase the line on the drawing 5 times, the real size would have to increase 5 times as well.
We can obviously see, after having said that, that the real window would have to be 35ft long (because we multiplied 1 inch by 5, and if 1 inch represents 7 feet, then we also have to multiply that by 5 so it’s proportional, and 7*5=35)
We can check too — 1 in : 7 ft = 5 in : x ft
x = (7ft * 5in) / 1in — we would get the same result :)
