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Finding the Fourth Proportional to 666.26, 997.86 and 643.20

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Solution

The fourth proportional to 666.26, 997.86 and 643.20 is: 963.32

Step by Step Solution

  1. Step 1: Write the proportion equation
    666.26 : 997.86 = 643.20 : x
  2. Step 2: Convert to fraction form
    666.26/997.86 = 643.20/x
  3. Step 3: Cross multiply
    666.26x = 997.86 × 643.20
  4. Step 4: Simplify right side
    666.26x = 641,823.55
  5. Step 5: Solve for x
    x = 641,823.55/666.26
  6. Step 6: Final answer
    x = 963.32

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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.