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Finding the Fourth Proportional to 689.05, 1,034.12 and 665.11

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Solution

The fourth proportional to 689.05, 1,034.12 and 665.11 is: 998.19

Step by Step Solution

  1. Step 1: Write the proportion equation
    689.05 : 1,034.12 = 665.11 : x
  2. Step 2: Convert to fraction form
    689.05/1,034.12 = 665.11/x
  3. Step 3: Cross multiply
    689.05x = 1,034.12 × 665.11
  4. Step 4: Simplify right side
    689.05x = 687,803.55
  5. Step 5: Solve for x
    x = 687,803.55/689.05
  6. Step 6: Final answer
    x = 998.19

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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.