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Finding the Fourth Proportional to 787.61, 1,083.80 and 644.54

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Solution

The fourth proportional to 787.61, 1,083.80 and 644.54 is: 886.92

Step by Step Solution

  1. Step 1: Write the proportion equation
    787.61 : 1,083.80 = 644.54 : x
  2. Step 2: Convert to fraction form
    787.61/1,083.80 = 644.54/x
  3. Step 3: Cross multiply
    787.61x = 1,083.80 × 644.54
  4. Step 4: Simplify right side
    787.61x = 698,543.81
  5. Step 5: Solve for x
    x = 698,543.81/787.61
  6. Step 6: Final answer
    x = 886.92

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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.