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Finding the Fourth Proportional to 641.72, 885.94 and 393.19

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Solution

The fourth proportional to 641.72, 885.94 and 393.19 is: 542.82

Step by Step Solution

  1. Step 1: Write the proportion equation
    641.72 : 885.94 = 393.19 : x
  2. Step 2: Convert to fraction form
    641.72/885.94 = 393.19/x
  3. Step 3: Cross multiply
    641.72x = 885.94 × 393.19
  4. Step 4: Simplify right side
    641.72x = 348,339.55
  5. Step 5: Solve for x
    x = 348,339.55/641.72
  6. Step 6: Final answer
    x = 542.82

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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.