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Finding the Fourth Proportional to 688.43, 949.09 and 666.89

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Solution

The fourth proportional to 688.43, 949.09 and 666.89 is: 919.39

Step by Step Solution

  1. Step 1: Write the proportion equation
    688.43 : 949.09 = 666.89 : x
  2. Step 2: Convert to fraction form
    688.43/949.09 = 666.89/x
  3. Step 3: Cross multiply
    688.43x = 949.09 × 666.89
  4. Step 4: Simplify right side
    688.43x = 632,939.34
  5. Step 5: Solve for x
    x = 632,939.34/688.43
  6. Step 6: Final answer
    x = 919.39

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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.