Find the sum of the geometric sequence. three divided by two, three divided by eight, three divided by thirty two, three divided by one hundred and twenty eight, three divided by five hundred and twelve

We have that
[3/2,3/8,3/32,3/128,3/512]

the sum of the geometric sequence is [3/2+3/8+3/32+3/128+3/512]
=(1/512)*[256*3+64*3+16*3+4*3]
=(3/512)*[256+64+16+4]
=(3/512)*[340]
=(1020/512)
=255/128> 1.9922

the answer is
1.9922

another way to calculate it 
is through the following formula
∑=ao*[(1-r^n)/(1-r)]

where 
ao> is the first term
r> is the common ratio between terms
n> is the number of terms
ao=1.5
r=1/4> 0.25
n=5
so
∑=1.5*[(1-0.25^5)/(1-0.25)]> 1.99