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Finding the Fourth Proportional to 642.18, 963.71 and 398.84

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Solution

The fourth proportional to 642.18, 963.71 and 398.84 is: 598.52

Step by Step Solution

  1. Step 1: Write the proportion equation
    642.18 : 963.71 = 398.84 : x
  2. Step 2: Convert to fraction form
    642.18/963.71 = 398.84/x
  3. Step 3: Cross multiply
    642.18x = 963.71 × 398.84
  4. Step 4: Simplify right side
    642.18x = 384,359.28
  5. Step 5: Solve for x
    x = 384,359.28/642.18
  6. Step 6: Final answer
    x = 598.52

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.