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Finding the Fourth Proportional to 641.70, 885.60 and 393.12

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Solution

The fourth proportional to 641.70, 885.60 and 393.12 is: 542.54

Step by Step Solution

  1. Step 1: Write the proportion equation
    641.70 : 885.60 = 393.12 : x
  2. Step 2: Convert to fraction form
    641.70/885.60 = 393.12/x
  3. Step 3: Cross multiply
    641.70x = 885.60 × 393.12
  4. Step 4: Simplify right side
    641.70x = 348,147.07
  5. Step 5: Solve for x
    x = 348,147.07/641.70
  6. Step 6: Final answer
    x = 542.54

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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.