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Finding the Fourth Proportional to 840.32, 1,259.92 and 515.60

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Solution

The fourth proportional to 840.32, 1,259.92 and 515.60 is: 773.06

Step by Step Solution

  1. Step 1: Write the proportion equation
    840.32 : 1,259.92 = 515.60 : x
  2. Step 2: Convert to fraction form
    840.32/1,259.92 = 515.60/x
  3. Step 3: Cross multiply
    840.32x = 1,259.92 × 515.60
  4. Step 4: Simplify right side
    840.32x = 649,614.75
  5. Step 5: Solve for x
    x = 649,614.75/840.32
  6. Step 6: Final answer
    x = 773.06

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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.