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Finding the Fourth Proportional to 689.45, 951.56 and 666.66

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Solution

The fourth proportional to 689.45, 951.56 and 666.66 is: 920.11

Step by Step Solution

  1. Step 1: Write the proportion equation
    689.45 : 951.56 = 666.66 : x
  2. Step 2: Convert to fraction form
    689.45/951.56 = 666.66/x
  3. Step 3: Cross multiply
    689.45x = 951.56 × 666.66
  4. Step 4: Simplify right side
    689.45x = 634,363.66
  5. Step 5: Solve for x
    x = 634,363.66/689.45
  6. Step 6: Final answer
    x = 920.11

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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.