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Finding the Fourth Proportional to 218.70, 329.64 and 206.15

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Solution

The fourth proportional to 218.70, 329.64 and 206.15 is: 310.72

Step by Step Solution

  1. Step 1: Write the proportion equation
    218.70 : 329.64 = 206.15 : x
  2. Step 2: Convert to fraction form
    218.70/329.64 = 206.15/x
  3. Step 3: Cross multiply
    218.70x = 329.64 × 206.15
  4. Step 4: Simplify right side
    218.70x = 67,953.64
  5. Step 5: Solve for x
    x = 67,953.64/218.70
  6. Step 6: Final answer
    x = 310.72

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Why These Related Problems?

These problems maintain the same ratio (1.51) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.