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Finding the Fourth Proportional to 819.10, 1,223.92 and 689.50

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Solution

The fourth proportional to 819.10, 1,223.92 and 689.50 is: 1,030.27

Step by Step Solution

  1. Step 1: Write the proportion equation
    819.10 : 1,223.92 = 689.50 : x
  2. Step 2: Convert to fraction form
    819.10/1,223.92 = 689.50/x
  3. Step 3: Cross multiply
    819.10x = 1,223.92 × 689.50
  4. Step 4: Simplify right side
    819.10x = 843,892.84
  5. Step 5: Solve for x
    x = 843,892.84/819.10
  6. Step 6: Final answer
    x = 1,030.27

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.