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Finding the Fourth Proportional to 787.88, 1,087.28 and 438.57

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Solution

The fourth proportional to 787.88, 1,087.28 and 438.57 is: 605.23

Step by Step Solution

  1. Step 1: Write the proportion equation
    787.88 : 1,087.28 = 438.57 : x
  2. Step 2: Convert to fraction form
    787.88/1,087.28 = 438.57/x
  3. Step 3: Cross multiply
    787.88x = 1,087.28 × 438.57
  4. Step 4: Simplify right side
    787.88x = 476,846.20
  5. Step 5: Solve for x
    x = 476,846.20/787.88
  6. Step 6: Final answer
    x = 605.23

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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.