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Finding the Fourth Proportional to 638.63, 881.31 and 355.05

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Solution

The fourth proportional to 638.63, 881.31 and 355.05 is: 489.97

Step by Step Solution

  1. Step 1: Write the proportion equation
    638.63 : 881.31 = 355.05 : x
  2. Step 2: Convert to fraction form
    638.63/881.31 = 355.05/x
  3. Step 3: Cross multiply
    638.63x = 881.31 × 355.05
  4. Step 4: Simplify right side
    638.63x = 312,904.71
  5. Step 5: Solve for x
    x = 312,904.71/638.63
  6. Step 6: Final answer
    x = 489.97

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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.