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Finding the Fourth Proportional to 642.40, 962.89 and 423.11

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Solution

The fourth proportional to 642.40, 962.89 and 423.11 is: 634.20

Step by Step Solution

  1. Step 1: Write the proportion equation
    642.40 : 962.89 = 423.11 : x
  2. Step 2: Convert to fraction form
    642.40/962.89 = 423.11/x
  3. Step 3: Cross multiply
    642.40x = 962.89 × 423.11
  4. Step 4: Simplify right side
    642.40x = 407,408.39
  5. Step 5: Solve for x
    x = 407,408.39/642.40
  6. Step 6: Final answer
    x = 634.20

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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.