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Finding the Fourth Proportional to 620.06, 855.92 and 420.80

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Solution

The fourth proportional to 620.06, 855.92 and 420.80 is: 580.86

Step by Step Solution

  1. Step 1: Write the proportion equation
    620.06 : 855.92 = 420.80 : x
  2. Step 2: Convert to fraction form
    620.06/855.92 = 420.80/x
  3. Step 3: Cross multiply
    620.06x = 855.92 × 420.80
  4. Step 4: Simplify right side
    620.06x = 360,165.54
  5. Step 5: Solve for x
    x = 360,165.54/620.06
  6. Step 6: Final answer
    x = 580.86

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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.