Answer & Step-by-step explanation:
To find if they have a constant of proportionality of 12, use the following:

Divide y by the x value (x,y), and if the remaining equation is true, then that table has a constant of proportionality of 12.*
:Done
*Make sure you check all the values in a table. Sometimes only the first values will have k=12, while the others don't.
**The constant of proportionality is represented by <em>k</em>.
I assume you're looking for n.
so, take 2n/10-3n/10=2/10. Making everything have the same denominator is always easier.
This way, you have -n/10=2/10.
n=-2.
a/b * b/c * c/d * d/e is equal to a/e provided that b, c, d,
and e are not zero
PROVE
a/b * b/c * c/d * d/e
= (a/b *b/c) * (c/d * d/e)
= ab/bc * (c/d * d/e)
= a/c * (c/d * d/e)
= a/c * (cd/de)
= a/c * c/e
= ac/ce
= a/e
Therefore, a/b * b/c * c/d * d/e is equal to a/e provided that
b, c, d, and e are not zero
if we take £15837.77 to be the 100% and we increase it by 18.5%, that'll be 100% + 18.5% = 118.5%.

Answer:
1. 8.3%
Step-by-step explanation:
Relative error = absolute error/expected measurement
The expected measurement is given as 6 ft.
Now, the absolute error is usually equal to half of a unit of the measure.
This means the absolute error in this case is ½ × 1 = 0.5 ft
Thus, the exact measurement will be;
6 ± 0.5
Thus;
Relative error = 0.5/6
Relative error = 0.083
Expressing it in percentage gives 8.3%