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Finding the Fourth Proportional to 621.02, 856.73 and 421.61

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Solution

The fourth proportional to 621.02, 856.73 and 421.61 is: 581.63

Step by Step Solution

  1. Step 1: Write the proportion equation
    621.02 : 856.73 = 421.61 : x
  2. Step 2: Convert to fraction form
    621.02/856.73 = 421.61/x
  3. Step 3: Cross multiply
    621.02x = 856.73 × 421.61
  4. Step 4: Simplify right side
    621.02x = 361,200.33
  5. Step 5: Solve for x
    x = 361,200.33/621.02
  6. Step 6: Final answer
    x = 581.63

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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.