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Finding the Fourth Proportional to 890.12, 1,227.21 and 688.43

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Solution

The fourth proportional to 890.12, 1,227.21 and 688.43 is: 949.14

Step by Step Solution

  1. Step 1: Write the proportion equation
    890.12 : 1,227.21 = 688.43 : x
  2. Step 2: Convert to fraction form
    890.12/1,227.21 = 688.43/x
  3. Step 3: Cross multiply
    890.12x = 1,227.21 × 688.43
  4. Step 4: Simplify right side
    890.12x = 844,842.04
  5. Step 5: Solve for x
    x = 844,842.04/890.12
  6. Step 6: Final answer
    x = 949.14

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.