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Finding the Fourth Proportional to 840.60, 1,260.90 and 456.60

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Solution

The fourth proportional to 840.60, 1,260.90 and 456.60 is: 684.90

Step by Step Solution

  1. Step 1: Write the proportion equation
    840.60 : 1,260.90 = 456.60 : x
  2. Step 2: Convert to fraction form
    840.60/1,260.90 = 456.60/x
  3. Step 3: Cross multiply
    840.60x = 1,260.90 × 456.60
  4. Step 4: Simplify right side
    840.60x = 575,726.94
  5. Step 5: Solve for x
    x = 575,726.94/840.60
  6. Step 6: Final answer
    x = 684.90

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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.