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Finding the Fourth Proportional to 485.78, 669.92 and 319.83

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Solution

The fourth proportional to 485.78, 669.92 and 319.83 is: 441.07

Step by Step Solution

  1. Step 1: Write the proportion equation
    485.78 : 669.92 = 319.83 : x
  2. Step 2: Convert to fraction form
    485.78/669.92 = 319.83/x
  3. Step 3: Cross multiply
    485.78x = 669.92 × 319.83
  4. Step 4: Simplify right side
    485.78x = 214,258.91
  5. Step 5: Solve for x
    x = 214,258.91/485.78
  6. Step 6: Final answer
    x = 441.07

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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.