Answer:
1979
91%
Explanation:
Given the relation :
P = (318t + 6792) / (1.19t + 107.36)
P = % of household with PC
t = years since 2000
1.) We need to find t, when P = 85%
P = 0.85
0.85 = (318t + 6792) / (1.19t + 107.36)
0.85(1.19t + 107.36) = (318t + 6792)
1.0115t + 91.256 = 318t + 6792
Collect like terms :
1.0115t - 318t = 6792 - 91.256
−316.9885t = 6700.744
t = 6700.744 / - 316.9885
t = - 21.138760
t = - 21 years
2000 - 21 years = 1979
Percentage who had computer in 2014
t = 2014 - 2000 = 14
P = (318(14) + 6792) / (1.19(14)+ 107.36)
P = (4452 + 6792) / (16.66 + 107.36)
P = 11244 / 124.02
P = 90.6627
P = approximately 91%