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Finding the Fourth Proportional to 218.80, 309.21 and 218.80

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Solution

The fourth proportional to 218.80, 309.21 and 218.80 is: 309.21

Step by Step Solution

  1. Step 1: Write the proportion equation
    218.80 : 309.21 = 218.80 : x
  2. Step 2: Convert to fraction form
    218.80/309.21 = 218.80/x
  3. Step 3: Cross multiply
    218.80x = 309.21 × 218.80
  4. Step 4: Simplify right side
    218.80x = 67,655.15
  5. Step 5: Solve for x
    x = 67,655.15/218.80
  6. Step 6: Final answer
    x = 309.21

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Why These Related Problems?

These problems maintain the same ratio (1.41) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.