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Finding the Fourth Proportional to 657.21, 985.76 and 218.42

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Solution

The fourth proportional to 657.21, 985.76 and 218.42 is: 327.61

Step by Step Solution

  1. Step 1: Write the proportion equation
    657.21 : 985.76 = 218.42 : x
  2. Step 2: Convert to fraction form
    657.21/985.76 = 218.42/x
  3. Step 3: Cross multiply
    657.21x = 985.76 × 218.42
  4. Step 4: Simplify right side
    657.21x = 215,309.70
  5. Step 5: Solve for x
    x = 215,309.70/657.21
  6. Step 6: Final answer
    x = 327.61

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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.