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Finding the Fourth Proportional to 640.80, 958.80 and 424.80

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Solution

The fourth proportional to 640.80, 958.80 and 424.80 is: 635.61

Step by Step Solution

  1. Step 1: Write the proportion equation
    640.80 : 958.80 = 424.80 : x
  2. Step 2: Convert to fraction form
    640.80/958.80 = 424.80/x
  3. Step 3: Cross multiply
    640.80x = 958.80 × 424.80
  4. Step 4: Simplify right side
    640.80x = 407,298.24
  5. Step 5: Solve for x
    x = 407,298.24/640.80
  6. Step 6: Final answer
    x = 635.61

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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.