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Finding the Fourth Proportional to 640.67, 961.29 and 478.67

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Solution

The fourth proportional to 640.67, 961.29 and 478.67 is: 718.22

Step by Step Solution

  1. Step 1: Write the proportion equation
    640.67 : 961.29 = 478.67 : x
  2. Step 2: Convert to fraction form
    640.67/961.29 = 478.67/x
  3. Step 3: Cross multiply
    640.67x = 961.29 × 478.67
  4. Step 4: Simplify right side
    640.67x = 460,135.88
  5. Step 5: Solve for x
    x = 460,135.88/640.67
  6. Step 6: Final answer
    x = 718.22

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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.