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Finding the Fourth Proportional to 789.72, 1,089.78 and 458.12

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Solution

The fourth proportional to 789.72, 1,089.78 and 458.12 is: 632.19

Step by Step Solution

  1. Step 1: Write the proportion equation
    789.72 : 1,089.78 = 458.12 : x
  2. Step 2: Convert to fraction form
    789.72/1,089.78 = 458.12/x
  3. Step 3: Cross multiply
    789.72x = 1,089.78 × 458.12
  4. Step 4: Simplify right side
    789.72x = 499,250.01
  5. Step 5: Solve for x
    x = 499,250.01/789.72
  6. Step 6: Final answer
    x = 632.19

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.