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Finding the Fourth Proportional to 840.69, 1,260.21 and 430.02

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Solution

The fourth proportional to 840.69, 1,260.21 and 430.02 is: 644.61

Step by Step Solution

  1. Step 1: Write the proportion equation
    840.69 : 1,260.21 = 430.02 : x
  2. Step 2: Convert to fraction form
    840.69/1,260.21 = 430.02/x
  3. Step 3: Cross multiply
    840.69x = 1,260.21 × 430.02
  4. Step 4: Simplify right side
    840.69x = 541,915.50
  5. Step 5: Solve for x
    x = 541,915.50/840.69
  6. Step 6: Final answer
    x = 644.61

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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.