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Finding the Fourth Proportional to 621.61, 856.81 and 442.22

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Solution

The fourth proportional to 621.61, 856.81 and 442.22 is: 609.54

Step by Step Solution

  1. Step 1: Write the proportion equation
    621.61 : 856.81 = 442.22 : x
  2. Step 2: Convert to fraction form
    621.61/856.81 = 442.22/x
  3. Step 3: Cross multiply
    621.61x = 856.81 × 442.22
  4. Step 4: Simplify right side
    621.61x = 378,894.79
  5. Step 5: Solve for x
    x = 378,894.79/621.61
  6. Step 6: Final answer
    x = 609.54

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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.