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Finding the Fourth Proportional to 640.11, 959.40 and 457.56

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Solution

The fourth proportional to 640.11, 959.40 and 457.56 is: 685.79

Step by Step Solution

  1. Step 1: Write the proportion equation
    640.11 : 959.40 = 457.56 : x
  2. Step 2: Convert to fraction form
    640.11/959.40 = 457.56/x
  3. Step 3: Cross multiply
    640.11x = 959.40 × 457.56
  4. Step 4: Simplify right side
    640.11x = 438,983.06
  5. Step 5: Solve for x
    x = 438,983.06/640.11
  6. Step 6: Final answer
    x = 685.79

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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.