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Finding the Fourth Proportional to 2,631, 3,946.92 and 987.78

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Solution

The fourth proportional to 2,631, 3,946.92 and 987.78 is: 1,481.83

Step by Step Solution

  1. Step 1: Write the proportion equation
    2,631 : 3,946.92 = 987.78 : x
  2. Step 2: Convert to fraction form
    2,631/3,946.92 = 987.78/x
  3. Step 3: Cross multiply
    2,631x = 3,946.92 × 987.78
  4. Step 4: Simplify right side
    2,631x = 3,898,688.64
  5. Step 5: Solve for x
    x = 3,898,688.64/2,631
  6. Step 6: Final answer
    x = 1,481.83

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1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.