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Finding the Fourth Proportional to 947.31, 1,421.07 and 485.11

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Solution

The fourth proportional to 947.31, 1,421.07 and 485.11 is: 727.72

Step by Step Solution

  1. Step 1: Write the proportion equation
    947.31 : 1,421.07 = 485.11 : x
  2. Step 2: Convert to fraction form
    947.31/1,421.07 = 485.11/x
  3. Step 3: Cross multiply
    947.31x = 1,421.07 × 485.11
  4. Step 4: Simplify right side
    947.31x = 689,375.27
  5. Step 5: Solve for x
    x = 689,375.27/947.31
  6. Step 6: Final answer
    x = 727.72

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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.