100%/x%=80/20
(100/x)*x=(80/20)*x - we multiply both sides of the equation by x
100=4*x - we divide both sides of the equation by (4) to get x
100/4=x
25=x
x=25
The interquartile range of the data set is 30.
Diane has 380 coins (rounded to the nearest 10)
One stratagie you can use is called the big 7