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Finding the Fourth Proportional to 620.68, 855.20 and 445.72

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Solution

The fourth proportional to 620.68, 855.20 and 445.72 is: 614.13

Step by Step Solution

  1. Step 1: Write the proportion equation
    620.68 : 855.20 = 445.72 : x
  2. Step 2: Convert to fraction form
    620.68/855.20 = 445.72/x
  3. Step 3: Cross multiply
    620.68x = 855.20 × 445.72
  4. Step 4: Simplify right side
    620.68x = 381,179.74
  5. Step 5: Solve for x
    x = 381,179.74/620.68
  6. Step 6: Final answer
    x = 614.13

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.