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Finding the Fourth Proportional to 752.50, 1,038.42 and 420.90

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Solution

The fourth proportional to 752.50, 1,038.42 and 420.90 is: 580.83

Step by Step Solution

  1. Step 1: Write the proportion equation
    752.50 : 1,038.42 = 420.90 : x
  2. Step 2: Convert to fraction form
    752.50/1,038.42 = 420.90/x
  3. Step 3: Cross multiply
    752.50x = 1,038.42 × 420.90
  4. Step 4: Simplify right side
    752.50x = 437,070.98
  5. Step 5: Solve for x
    x = 437,070.98/752.50
  6. Step 6: Final answer
    x = 580.83

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.