Find the sum of the first six terms of the sequence for which a2 = 0.7 and a3 = 0.49

Question

anonymous · Answer

@terenzreignz sorry! I just have one more

terenzreignz · Answer

These questions are so different from one another... this isn't an exam, is it? -_-

anonymous · Answer

No it is not an exam... it is a study guide for my test tomorrow

campbell_st · Answer

well the series is geometric based on the information 

a general term is 

$$a_{n} = a_{1} r^{n-1}$$

a1 = 1st term, r = common ratio

so start by finding the common ratio

2nd term 
$$0.7 = ar$$

3rd term

$$0.49 = ar^2... or..... 0.49 = (ar) \times r   ...or...... 0.49 = 0.7 \times r$$

so the common ratio is 0.7 and the 1st term is 1

then the you can use this information with n = 6 to find the sum

anonymous · Answer

so it goes 1,0.7,0.49...

anonymous · Answer

So is 2.94 the sum of the first 6?