Honi is looking at a map with a scale of 1 4 in. = 20 miles. she measured the distance from niceville to live oak as 2.5 in. she found the actual distance between niceville and live oak by following these steps:

step 1: set up a proportion 1 4 20 = 2.5 x
step 2: cross multiply (20)(2.5) = ( 1 4 )(x)
step 3: simplify 50 = 1 4 x
step 4: solve for x, x = 250 miles
which step, if any, contains a mistake?
a) step 1
b) step 2
c) step 3
d) step 4

The correct question is
Honi is looking at a map with a scale of 1/4 in. = 20 miles. She measured the distance from Niceville to Live Oak as 2.5 in. She found the actual distance between Niceville and Live Oak by following these steps:

Step 1: Set up a proportion 1/4/20 = 2.5/ x 
Step 2: Cross multiply (20)(2.5) = ( 1/4 )(x) 
Step 3: Simplify 50 = 1/4 x 
Step 4: Solve for x, x = 250 miles 
Which step, if any, contains a mistake?

we have that
Step 1: Set up a proportion 1/4/20 = 2.5/ x > is correct
Step 2: Cross multiply (20)(2.5) = ( 1/4 )(x) > is correct
Step 3: Simplify 50 = 1/4 x > is correct

Step 4: Solve for x, x = 250 miles > is not correct
because in the step 3  we have > 50=(1/4)*x
x=50*4> x=200 miles

the answer the option D)  Step 4

Hmm confusing don't understand