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Finding the Fourth Proportional to 684.90, 1,027.89 and 642.42

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Solution

The fourth proportional to 684.90, 1,027.89 and 642.42 is: 964.14

Step by Step Solution

  1. Step 1: Write the proportion equation
    684.90 : 1,027.89 = 642.42 : x
  2. Step 2: Convert to fraction form
    684.90/1,027.89 = 642.42/x
  3. Step 3: Cross multiply
    684.90x = 1,027.89 × 642.42
  4. Step 4: Simplify right side
    684.90x = 660,337.09
  5. Step 5: Solve for x
    x = 660,337.09/684.90
  6. Step 6: Final answer
    x = 964.14

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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.