It is 71.4285% (to be exact) increase
The answer is 12 ÷ 4 + 13 > 2 + 22 ÷ 2
Formula applied: p+/- Z*sqrt (p(1-p)/N)
Where
p=probability of those who will vote for candidate a = 120/400 = 0.3
Z = Critical value at 95% confidence interval = 1.96
N = Size of the sample = 400
Substituting;
Interval = 0.3+/- 1.96* sqrt (0.3(1-0.3)/400) = 0.3+/-0.045
Interval of population who will vote for candidate a at 95% confidence interval
= 0.3+0.045 to 0.3-0.045
=0.345 to 0.255 of the total population
Original price = 22000
New price = 2500
Amount depreciated in 5 years = 22000 - 2500
=19500
Amount depreciated in 1 year = 19500/5
= 3900
Worth after 3 years = 22000 - 3(3900)
= 10300