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Finding the Fourth Proportional to 1,389.94, 2,085.38 and 512.30

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Solution

The fourth proportional to 1,389.94, 2,085.38 and 512.30 is: 768.62

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,389.94 : 2,085.38 = 512.30 : x
  2. Step 2: Convert to fraction form
    1,389.94/2,085.38 = 512.30/x
  3. Step 3: Cross multiply
    1,389.94x = 2,085.38 × 512.30
  4. Step 4: Simplify right side
    1,389.94x = 1,068,340.17
  5. Step 5: Solve for x
    x = 1,068,340.17/1,389.94
  6. Step 6: Final answer
    x = 768.62

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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.