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Finding the Fourth Proportional to 1,280.31, 1,920.67 and 458.36

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Solution

The fourth proportional to 1,280.31, 1,920.67 and 458.36 is: 687.61

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,280.31 : 1,920.67 = 458.36 : x
  2. Step 2: Convert to fraction form
    1,280.31/1,920.67 = 458.36/x
  3. Step 3: Cross multiply
    1,280.31x = 1,920.67 × 458.36
  4. Step 4: Simplify right side
    1,280.31x = 880,358.30
  5. Step 5: Solve for x
    x = 880,358.30/1,280.31
  6. Step 6: Final answer
    x = 687.61

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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.