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Finding the Fourth Proportional to 640.12, 958.74 and 457.72

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Solution

The fourth proportional to 640.12, 958.74 and 457.72 is: 685.55

Step by Step Solution

  1. Step 1: Write the proportion equation
    640.12 : 958.74 = 457.72 : x
  2. Step 2: Convert to fraction form
    640.12/958.74 = 457.72/x
  3. Step 3: Cross multiply
    640.12x = 958.74 × 457.72
  4. Step 4: Simplify right side
    640.12x = 438,834.47
  5. Step 5: Solve for x
    x = 438,834.47/640.12
  6. Step 6: Final answer
    x = 685.55

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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.