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Finding the Fourth Proportional to 787.94, 1,087.39 and 438.63

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Solution

The fourth proportional to 787.94, 1,087.39 and 438.63 is: 605.32

Step by Step Solution

  1. Step 1: Write the proportion equation
    787.94 : 1,087.39 = 438.63 : x
  2. Step 2: Convert to fraction form
    787.94/1,087.39 = 438.63/x
  3. Step 3: Cross multiply
    787.94x = 1,087.39 × 438.63
  4. Step 4: Simplify right side
    787.94x = 476,956.44
  5. Step 5: Solve for x
    x = 476,956.44/787.94
  6. Step 6: Final answer
    x = 605.32

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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.