Answer:
Step-by-step explanation:
Given the explicit function as
f(n) = 15n+4
The first term of the sequence is at when n= 1
f(1) = 15(1)+4
f(1) = 19
a = 19
Common difference d = f(2)-f(1)
f(2) = 15(2)+4
f(2) = 34
d = 34-19
d = 15
Sum of nth term of an AP = n/2{2a+(n-1)d}
S20 = 20/2{2(19)+(20-1)15)
S20 = 10(38+19(15))
S20 = 10(38+285)
S20 = 10(323)
S20 = 3230.
Sum of the 20th term is 3230
For the explicit function
f(n) = 4n+15
f(1) = 4(1)+15
f(1) = 19
a = 19
Common difference d = f(2)-f(1)
f(2) = 4(2)+15
f(2) = 23
d = 23-19
d = 4
Sum of nth term of an AP = n/2{2a+(n-1)d}
S20 = 20/2{2(19)+(20-1)4)
S20 = 10(38+19(4))
S20 = 10(38+76)
S20 = 10(114)
S20 = 1140
Sum of the 20th terms is 1140
He didn’t divide before he multiplied
Find the mean of thw data 11,11,12,13,13,13,14,14,15,15,16,16,18
amid [387]
Answer:
the mean is 13
Step-by-step explanation:
The way to find the mean of a set of numbers is to add all the numbers together and divide the sum by the number of numbers. so 11 + 11 + 12 + 13+ 13 + 13 + 14 + 14 + 15 + 15 + 16 + 16 + 18 / 13 = 13.9
You can tell if it’s linear if the numbers are going up by the same number
