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Finding the Fourth Proportional to 687.14, 1,028.84 and 394.38

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Solution

The fourth proportional to 687.14, 1,028.84 and 394.38 is: 590.50

Step by Step Solution

  1. Step 1: Write the proportion equation
    687.14 : 1,028.84 = 394.38 : x
  2. Step 2: Convert to fraction form
    687.14/1,028.84 = 394.38/x
  3. Step 3: Cross multiply
    687.14x = 1,028.84 × 394.38
  4. Step 4: Simplify right side
    687.14x = 405,751.95
  5. Step 5: Solve for x
    x = 405,751.95/687.14
  6. Step 6: Final answer
    x = 590.50

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.