Statistics: Sequences

1. The first four terms in a sequence are shown above. Each term after the first is found by multiplying each term by $\dfrac{-1}{2}$. What is the 7th term in the sequence?

ANSWER: (C)$1\dfrac{3}{8}$

The fourth term is -11. Multiply that by-1/2. You get 11/2. Multiply that by -1/2. You get -11/4. multiply that by -1/2. You will get 11/8. This is the 7th term. Turn 11/8 into a mixed number and you get *drum roll please* 1 and 3/8!

The first five terms are shown above. Each term after the first is found by adding the previous term to the current one. Using the sequence above, what the 8th term in the sequence?

ANSWER: (D)21

1+1=2 (3rd term). 2+1=3 (4th term). 3+2=5 (5th term). 5+3= 8 (6th term). 8+5=13 (7th term). 13+8=21 (8th term)

3. The first five terms in a sequence are shown above. Each term after the first is found by adding -12 to the term immediately preceding it. Which term in this sequence is equal to $6 + (9-1)-12$?

ANSWER: (B)The 9th

In the sequence above, each term after the first term is 20% of the term preceding it, What is the fifth term in this sequence?

ANSWER: .096