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Finding the Fourth Proportional to 787.87, 1,088.31 and 642.34

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Solution

The fourth proportional to 787.87, 1,088.31 and 642.34 is: 887.28

Step by Step Solution

  1. Step 1: Write the proportion equation
    787.87 : 1,088.31 = 642.34 : x
  2. Step 2: Convert to fraction form
    787.87/1,088.31 = 642.34/x
  3. Step 3: Cross multiply
    787.87x = 1,088.31 × 642.34
  4. Step 4: Simplify right side
    787.87x = 699,065.05
  5. Step 5: Solve for x
    x = 699,065.05/787.87
  6. Step 6: Final answer
    x = 887.28

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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.