Let us check series : -10 /-2 = 5 -50/-10 = 5
so it is a geometric series with a= -2 and r= 5
sum formula for n terms of geometric series = a ( r^n -1 ) /( r-1)
here we find S5 that is n= 5 = -2 ( 5^ 5 - 1) /( 5-1)
= -2 ( 3125 -1) / 4 = -1562
second series is : 1.5/1 = 1.5 2.25/1.5 = 1.5
this is also geometric series but n = 12 a= 1 and r= 1.5
we use same formula
S12 = 1 ( (1.5) ^12 -1) /( 1.5-1) =
128.74 / 0.5 = 257.49
Last is 2/1= 2 4/2 = 2 8/4 = 2 so r = 2 a = 1 and n = 12
we use same formula 1 ( 2^12 - 1) / (2-1)
= 4095
Answers : -1562 , 257.49 , 4095
1. D. because if the students she surveyed had just left the movie theatre, meaning they were there to watch a movie, hence the conclusion that they like watching movies can be drawn. 2. D. because the same reason as number 1, the reporter only surveyed people that had shopped there, meaning that the people liked Forever 21 merchandise.
Answer:
range= y>0 domain is all real numbers
y intercept is 1
