Home / 56.80-85.16-18.80

Finding the Fourth Proportional to 56.80, 85.16 and 18.80

Calculator

Solution

The fourth proportional to 56.80, 85.16 and 18.80 is: 28.19

Step by Step Solution

  1. Step 1: Write the proportion equation
    56.80 : 85.16 = 18.80 : x
  2. Step 2: Convert to fraction form
    56.80/85.16 = 18.80/x
  3. Step 3: Cross multiply
    56.80x = 85.16 × 18.80
  4. Step 4: Simplify right side
    56.80x = 1,601.01
  5. Step 5: Solve for x
    x = 1,601.01/56.80
  6. Step 6: Final answer
    x = 28.19

Related Problems

Find fourth proportional to 28.40, 42.58 and 9.40
Half scale
Find fourth proportional to 113.60, 170.32 and 37.60
Double scale
Find fourth proportional to 57.80, 86.66 and 19.80
Similar ratio
Find fourth proportional to 85.20, 127.74 and 28.20
1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.