It helps you determine the characteristics of the plot/graph. I am not sure so it is your choose.
Answer for the first one is just 7/9, 28/36
Second one is 9/14, 3/4
For the third one you multiply 12.50 by 5 which gives you 62.5
So sig figs are non zero so
500 has 1 sig fig, 5
but 500. has 3 sig figs because it has a decimal
2.3 has 2 sig figs
2.03 has 3 sig figs so to make 232.76 to 2 sig figs you would put it into scientific notation and get 2.3 times 10^2 and thats 2 sig figs (the 10^2 doesn't count as a sig fig)
112 let me explain
4 styles times 4 stitch options times 7 equals 112
the value of r of the geometric series n=11.3(0.8)n-1
General formula for nth term of any geometric series is 
Here 'r' is the common ratio
a_1 is the first term of the series
Now we compare the given formula with general formula
Compare with
The value of r= 0.8
