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Finding the Fourth Proportional to 485.60, 728.39 and 207.91

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Solution

The fourth proportional to 485.60, 728.39 and 207.91 is: 311.86

Step by Step Solution

  1. Step 1: Write the proportion equation
    485.60 : 728.39 = 207.91 : x
  2. Step 2: Convert to fraction form
    485.60/728.39 = 207.91/x
  3. Step 3: Cross multiply
    485.60x = 728.39 × 207.91
  4. Step 4: Simplify right side
    485.60x = 151,437.74
  5. Step 5: Solve for x
    x = 151,437.74/485.60
  6. Step 6: Final answer
    x = 311.86

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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.