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Finding the Fourth Proportional to 218.61, 300.78 and 213.21

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Solution

The fourth proportional to 218.61, 300.78 and 213.21 is: 293.35

Step by Step Solution

  1. Step 1: Write the proportion equation
    218.61 : 300.78 = 213.21 : x
  2. Step 2: Convert to fraction form
    218.61/300.78 = 213.21/x
  3. Step 3: Cross multiply
    218.61x = 300.78 × 213.21
  4. Step 4: Simplify right side
    218.61x = 64,129.30
  5. Step 5: Solve for x
    x = 64,129.30/218.61
  6. Step 6: Final answer
    x = 293.35

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.