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Finding the Fourth Proportional to 642.68, 964.01 and 426.20

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Solution

The fourth proportional to 642.68, 964.01 and 426.20 is: 639.29

Step by Step Solution

  1. Step 1: Write the proportion equation
    642.68 : 964.01 = 426.20 : x
  2. Step 2: Convert to fraction form
    642.68/964.01 = 426.20/x
  3. Step 3: Cross multiply
    642.68x = 964.01 × 426.20
  4. Step 4: Simplify right side
    642.68x = 410,854.11
  5. Step 5: Solve for x
    x = 410,854.11/642.68
  6. Step 6: Final answer
    x = 639.29

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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.