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Finding the Fourth Proportional to 840.81, 1,260.39 and 430.14

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Solution

The fourth proportional to 840.81, 1,260.39 and 430.14 is: 644.79

Step by Step Solution

  1. Step 1: Write the proportion equation
    840.81 : 1,260.39 = 430.14 : x
  2. Step 2: Convert to fraction form
    840.81/1,260.39 = 430.14/x
  3. Step 3: Cross multiply
    840.81x = 1,260.39 × 430.14
  4. Step 4: Simplify right side
    840.81x = 542,144.15
  5. Step 5: Solve for x
    x = 542,144.15/840.81
  6. Step 6: Final answer
    x = 644.79

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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.