Don't you think you need to state whether this is an AP or GP?

If you should decide to do so, I MIGHT give you the answer, or even work it out for you. 

RELATED QUESTIONS

Find A1 and d for an arithmetic sequence with these terms:

A4 = 9 

A7 =... (answered by josgarithmetic)

Find a1 and d for an arithmetic sequence with these terms: a4=9 and... (answered by richwmiller)

For an arithmetic progression, a1, a2, a3,..... aN, if a4/a7=2/3, find a6/a8.  (answered by greenestamps)

2,6,11,17, ...a7 find... (answered by Fombitz)

2,611,17, ...a7 find... (answered by Fombitz)

Find a1 if Sn=468, an=375, and... (answered by fractalier)

I have trouble with these remaining problems i could use some help answering these thank... (answered by venugopalramana)

Find n if Sn =55
 (answered by richwmiller)

1) In an arithmetic sequence, a4=8 and a7=26. Find a1 and d. Write the first 5 terms of... (answered by mananth,ikleyn)