<em><u>Answer:</u></em>
Natasha should have multiplied 140 by 2
Let the original number be
x
x
×
160
100
=
192
. This indicates an increase of 60%
x
=
192
×
100
160
x
=
120
10% of 26.80 = 2.68
5% of 2.68 = 1.34
2.68 + 1.34 = 4.02
Your best estimate is 4.05