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Finding the Fourth Proportional to 218.65, 328.11 and 198.40

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Solution

The fourth proportional to 218.65, 328.11 and 198.40 is: 297.72

Step by Step Solution

  1. Step 1: Write the proportion equation
    218.65 : 328.11 = 198.40 : x
  2. Step 2: Convert to fraction form
    218.65/328.11 = 198.40/x
  3. Step 3: Cross multiply
    218.65x = 328.11 × 198.40
  4. Step 4: Simplify right side
    218.65x = 65,097.02
  5. Step 5: Solve for x
    x = 65,097.02/218.65
  6. Step 6: Final answer
    x = 297.72

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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.