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Finding the Fourth Proportional to 642.09, 885.92 and 393.32

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Solution

The fourth proportional to 642.09, 885.92 and 393.32 is: 542.68

Step by Step Solution

  1. Step 1: Write the proportion equation
    642.09 : 885.92 = 393.32 : x
  2. Step 2: Convert to fraction form
    642.09/885.92 = 393.32/x
  3. Step 3: Cross multiply
    642.09x = 885.92 × 393.32
  4. Step 4: Simplify right side
    642.09x = 348,445.87
  5. Step 5: Solve for x
    x = 348,445.87/642.09
  6. Step 6: Final answer
    x = 542.68

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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.