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Finding the Fourth Proportional to 641.72, 885.66 and 393.00

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Solution

The fourth proportional to 641.72, 885.66 and 393.00 is: 542.39

Step by Step Solution

  1. Step 1: Write the proportion equation
    641.72 : 885.66 = 393.00 : x
  2. Step 2: Convert to fraction form
    641.72/885.66 = 393.00/x
  3. Step 3: Cross multiply
    641.72x = 885.66 × 393.00
  4. Step 4: Simplify right side
    641.72x = 348,059.95
  5. Step 5: Solve for x
    x = 348,059.95/641.72
  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.