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Finding the Fourth Proportional to 620.70, 856.14 and 423.90

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Solution

The fourth proportional to 620.70, 856.14 and 423.90 is: 584.69

Step by Step Solution

  1. Step 1: Write the proportion equation
    620.70 : 856.14 = 423.90 : x
  2. Step 2: Convert to fraction form
    620.70/856.14 = 423.90/x
  3. Step 3: Cross multiply
    620.70x = 856.14 × 423.90
  4. Step 4: Simplify right side
    620.70x = 362,917.75
  5. Step 5: Solve for x
    x = 362,917.75/620.70
  6. Step 6: Final answer
    x = 584.69

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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.