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Finding the Fourth Proportional to 640.96, 961.28 and 178.72

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Solution

The fourth proportional to 640.96, 961.28 and 178.72 is: 268.04

Step by Step Solution

  1. Step 1: Write the proportion equation
    640.96 : 961.28 = 178.72 : x
  2. Step 2: Convert to fraction form
    640.96/961.28 = 178.72/x
  3. Step 3: Cross multiply
    640.96x = 961.28 × 178.72
  4. Step 4: Simplify right side
    640.96x = 171,803.75
  5. Step 5: Solve for x
    x = 171,803.75/640.96
  6. Step 6: Final answer
    x = 268.04

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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.