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Finding the Fourth Proportional to 669.72, 996.63 and 643.80

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Solution

The fourth proportional to 669.72, 996.63 and 643.80 is: 958.06

Step by Step Solution

  1. Step 1: Write the proportion equation
    669.72 : 996.63 = 643.80 : x
  2. Step 2: Convert to fraction form
    669.72/996.63 = 643.80/x
  3. Step 3: Cross multiply
    669.72x = 996.63 × 643.80
  4. Step 4: Simplify right side
    669.72x = 641,630.39
  5. Step 5: Solve for x
    x = 641,630.39/669.72
  6. Step 6: Final answer
    x = 958.06

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.