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Finding the Fourth Proportional to 1,125, 1,687.50 and 394.38

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Solution

The fourth proportional to 1,125, 1,687.50 and 394.38 is: 591.57

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,125 : 1,687.50 = 394.38 : x
  2. Step 2: Convert to fraction form
    1,125/1,687.50 = 394.38/x
  3. Step 3: Cross multiply
    1,125x = 1,687.50 × 394.38
  4. Step 4: Simplify right side
    1,125x = 665,516.25
  5. Step 5: Solve for x
    x = 665,516.25/1,125
  6. Step 6: Final answer
    x = 591.57

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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.