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Finding the Fourth Proportional to 787.61, 1,086.93 and 438.30

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Solution

The fourth proportional to 787.61, 1,086.93 and 438.30 is: 604.87

Step by Step Solution

  1. Step 1: Write the proportion equation
    787.61 : 1,086.93 = 438.30 : x
  2. Step 2: Convert to fraction form
    787.61/1,086.93 = 438.30/x
  3. Step 3: Cross multiply
    787.61x = 1,086.93 × 438.30
  4. Step 4: Simplify right side
    787.61x = 476,401.42
  5. Step 5: Solve for x
    x = 476,401.42/787.61
  6. Step 6: Final answer
    x = 604.87

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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.