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Finding the Fourth Proportional to 218.86, 328.12 and 72.55

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Solution

The fourth proportional to 218.86, 328.12 and 72.55 is: 108.77

Step by Step Solution

  1. Step 1: Write the proportion equation
    218.86 : 328.12 = 72.55 : x
  2. Step 2: Convert to fraction form
    218.86/328.12 = 72.55/x
  3. Step 3: Cross multiply
    218.86x = 328.12 × 72.55
  4. Step 4: Simplify right side
    218.86x = 23,805.11
  5. Step 5: Solve for x
    x = 23,805.11/218.86
  6. Step 6: Final answer
    x = 108.77

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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.