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Finding the Fourth Proportional to 687.90, 1,031.05 and 297.77

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Solution

The fourth proportional to 687.90, 1,031.05 and 297.77 is: 446.31

Step by Step Solution

  1. Step 1: Write the proportion equation
    687.90 : 1,031.05 = 297.77 : x
  2. Step 2: Convert to fraction form
    687.90/1,031.05 = 297.77/x
  3. Step 3: Cross multiply
    687.90x = 1,031.05 × 297.77
  4. Step 4: Simplify right side
    687.90x = 307,015.76
  5. Step 5: Solve for x
    x = 307,015.76/687.90
  6. Step 6: Final answer
    x = 446.31

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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.