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Finding the Fourth Proportional to 787.86, 1,087.29 and 438.54

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Solution

The fourth proportional to 787.86, 1,087.29 and 438.54 is: 605.21

Step by Step Solution

  1. Step 1: Write the proportion equation
    787.86 : 1,087.29 = 438.54 : x
  2. Step 2: Convert to fraction form
    787.86/1,087.29 = 438.54/x
  3. Step 3: Cross multiply
    787.86x = 1,087.29 × 438.54
  4. Step 4: Simplify right side
    787.86x = 476,820.16
  5. Step 5: Solve for x
    x = 476,820.16/787.86
  6. Step 6: Final answer
    x = 605.21

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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.