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Finding the Fourth Proportional to 640.47, 960.95 and 255.75

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Solution

The fourth proportional to 640.47, 960.95 and 255.75 is: 383.72

Step by Step Solution

  1. Step 1: Write the proportion equation
    640.47 : 960.95 = 255.75 : x
  2. Step 2: Convert to fraction form
    640.47/960.95 = 255.75/x
  3. Step 3: Cross multiply
    640.47x = 960.95 × 255.75
  4. Step 4: Simplify right side
    640.47x = 245,761.68
  5. Step 5: Solve for x
    x = 245,761.68/640.47
  6. Step 6: Final answer
    x = 383.72

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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.