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Finding the Fourth Proportional to 787.71, 1,087.05 and 456.15

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Solution

The fourth proportional to 787.71, 1,087.05 and 456.15 is: 629.49

Step by Step Solution

  1. Step 1: Write the proportion equation
    787.71 : 1,087.05 = 456.15 : x
  2. Step 2: Convert to fraction form
    787.71/1,087.05 = 456.15/x
  3. Step 3: Cross multiply
    787.71x = 1,087.05 × 456.15
  4. Step 4: Simplify right side
    787.71x = 495,857.86
  5. Step 5: Solve for x
    x = 495,857.86/787.71
  6. Step 6: Final answer
    x = 629.49

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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.