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Finding the Fourth Proportional to 620.61, 856.47 and 355.09

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Solution

The fourth proportional to 620.61, 856.47 and 355.09 is: 490.04

Step by Step Solution

  1. Step 1: Write the proportion equation
    620.61 : 856.47 = 355.09 : x
  2. Step 2: Convert to fraction form
    620.61/856.47 = 355.09/x
  3. Step 3: Cross multiply
    620.61x = 856.47 × 355.09
  4. Step 4: Simplify right side
    620.61x = 304,123.93
  5. Step 5: Solve for x
    x = 304,123.93/620.61
  6. Step 6: Final answer
    x = 490.04

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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.