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Finding the Fourth Proportional to 840.30, 1,260.66 and 429.06

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Solution

The fourth proportional to 840.30, 1,260.66 and 429.06 is: 643.70

Step by Step Solution

  1. Step 1: Write the proportion equation
    840.30 : 1,260.66 = 429.06 : x
  2. Step 2: Convert to fraction form
    840.30/1,260.66 = 429.06/x
  3. Step 3: Cross multiply
    840.30x = 1,260.66 × 429.06
  4. Step 4: Simplify right side
    840.30x = 540,898.78
  5. Step 5: Solve for x
    x = 540,898.78/840.30
  6. Step 6: Final answer
    x = 643.70

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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.