Home / 381.60-572.40-138.36

Finding the Fourth Proportional to 381.60, 572.40 and 138.36

Calculator

Solution

The fourth proportional to 381.60, 572.40 and 138.36 is: 207.54

Step by Step Solution

  1. Step 1: Write the proportion equation
    381.60 : 572.40 = 138.36 : x
  2. Step 2: Convert to fraction form
    381.60/572.40 = 138.36/x
  3. Step 3: Cross multiply
    381.60x = 572.40 × 138.36
  4. Step 4: Simplify right side
    381.60x = 79,197.26
  5. Step 5: Solve for x
    x = 79,197.26/381.60
  6. Step 6: Final answer
    x = 207.54

Related Problems

Find fourth proportional to 190.80, 286.20 and 69.18
Half scale
Find fourth proportional to 763.20, 1,144.80 and 276.72
Double scale
Find fourth proportional to 382.60, 573.90 and 139.36
Similar ratio
Find fourth proportional to 572.40, 858.60 and 207.54
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.