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Finding the Fourth Proportional to 620.15, 855.86 and 409.96

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Solution

The fourth proportional to 620.15, 855.86 and 409.96 is: 565.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    620.15 : 855.86 = 409.96 : x
  2. Step 2: Convert to fraction form
    620.15/855.86 = 409.96/x
  3. Step 3: Cross multiply
    620.15x = 855.86 × 409.96
  4. Step 4: Simplify right side
    620.15x = 350,869.79
  5. Step 5: Solve for x
    x = 350,869.79/620.15
  6. Step 6: Final answer
    x = 565.78

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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.