Home / 558.20-837.30-428.60

Finding the Fourth Proportional to 558.20, 837.30 and 428.60

Calculator

Solution

The fourth proportional to 558.20, 837.30 and 428.60 is: 642.90

Step by Step Solution

  1. Step 1: Write the proportion equation
    558.20 : 837.30 = 428.60 : x
  2. Step 2: Convert to fraction form
    558.20/837.30 = 428.60/x
  3. Step 3: Cross multiply
    558.20x = 837.30 × 428.60
  4. Step 4: Simplify right side
    558.20x = 358,866.78
  5. Step 5: Solve for x
    x = 358,866.78/558.20
  6. Step 6: Final answer
    x = 642.90

Related Problems

Find fourth proportional to 279.10, 418.65 and 214.30
Half scale
Find fourth proportional to 1,116.40, 1,674.60 and 857.20
Double scale
Find fourth proportional to 559.20, 838.80 and 429.60
Similar ratio
Find fourth proportional to 837.30, 1,255.95 and 642.90
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.