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Finding the Fourth Proportional to 1,200.57, 1,800.20 and 420.37

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Solution

The fourth proportional to 1,200.57, 1,800.20 and 420.37 is: 630.33

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,200.57 : 1,800.20 = 420.37 : x
  2. Step 2: Convert to fraction form
    1,200.57/1,800.20 = 420.37/x
  3. Step 3: Cross multiply
    1,200.57x = 1,800.20 × 420.37
  4. Step 4: Simplify right side
    1,200.57x = 756,751.12
  5. Step 5: Solve for x
    x = 756,751.12/1,200.57
  6. Step 6: Final answer
    x = 630.33

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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.