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Finding the Fourth Proportional to 642.17, 886.18 and 393.50

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Solution

The fourth proportional to 642.17, 886.18 and 393.50 is: 543.02

Step by Step Solution

  1. Step 1: Write the proportion equation
    642.17 : 886.18 = 393.50 : x
  2. Step 2: Convert to fraction form
    642.17/886.18 = 393.50/x
  3. Step 3: Cross multiply
    642.17x = 886.18 × 393.50
  4. Step 4: Simplify right side
    642.17x = 348,711.83
  5. Step 5: Solve for x
    x = 348,711.83/642.17
  6. Step 6: Final answer
    x = 543.02

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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.