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Finding the Fourth Proportional to 641.80, 885.68 and 393.04

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Solution

The fourth proportional to 641.80, 885.68 and 393.04 is: 542.39

Step by Step Solution

  1. Step 1: Write the proportion equation
    641.80 : 885.68 = 393.04 : x
  2. Step 2: Convert to fraction form
    641.80/885.68 = 393.04/x
  3. Step 3: Cross multiply
    641.80x = 885.68 × 393.04
  4. Step 4: Simplify right side
    641.80x = 348,107.67
  5. Step 5: Solve for x
    x = 348,107.67/641.80
  6. Step 6: Final answer
    x = 542.39

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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.