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Finding the Fourth Proportional to 663.45, 995.18 and 643.39

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Solution

The fourth proportional to 663.45, 995.18 and 643.39 is: 965.09

Step by Step Solution

  1. Step 1: Write the proportion equation
    663.45 : 995.18 = 643.39 : x
  2. Step 2: Convert to fraction form
    663.45/995.18 = 643.39/x
  3. Step 3: Cross multiply
    663.45x = 995.18 × 643.39
  4. Step 4: Simplify right side
    663.45x = 640,288.86
  5. Step 5: Solve for x
    x = 640,288.86/663.45
  6. Step 6: Final answer
    x = 965.09

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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.