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Finding the Fourth Proportional to 816.72, 1,229.84 and 687.84

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Solution

The fourth proportional to 816.72, 1,229.84 and 687.84 is: 1,035.77

Step by Step Solution

  1. Step 1: Write the proportion equation
    816.72 : 1,229.84 = 687.84 : x
  2. Step 2: Convert to fraction form
    816.72/1,229.84 = 687.84/x
  3. Step 3: Cross multiply
    816.72x = 1,229.84 × 687.84
  4. Step 4: Simplify right side
    816.72x = 845,933.15
  5. Step 5: Solve for x
    x = 845,933.15/816.72
  6. Step 6: Final answer
    x = 1,035.77

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Why These Related Problems?

These problems maintain the same ratio (1.51) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.