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Finding the Fourth Proportional to 642.39, 886.50 and 409.92

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Solution

The fourth proportional to 642.39, 886.50 and 409.92 is: 565.69

Step by Step Solution

  1. Step 1: Write the proportion equation
    642.39 : 886.50 = 409.92 : x
  2. Step 2: Convert to fraction form
    642.39/886.50 = 409.92/x
  3. Step 3: Cross multiply
    642.39x = 886.50 × 409.92
  4. Step 4: Simplify right side
    642.39x = 363,394.08
  5. Step 5: Solve for x
    x = 363,394.08/642.39
  6. Step 6: Final answer
    x = 565.69

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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.