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Finding the Fourth Proportional to 620.48, 855.84 and 387.68

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Solution

The fourth proportional to 620.48, 855.84 and 387.68 is: 534.73

Step by Step Solution

  1. Step 1: Write the proportion equation
    620.48 : 855.84 = 387.68 : x
  2. Step 2: Convert to fraction form
    620.48/855.84 = 387.68/x
  3. Step 3: Cross multiply
    620.48x = 855.84 × 387.68
  4. Step 4: Simplify right side
    620.48x = 331,792.05
  5. Step 5: Solve for x
    x = 331,792.05/620.48
  6. Step 6: Final answer
    x = 534.73

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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.