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Finding the Fourth Proportional to 218.28, 325.36 and 211.80

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Solution

The fourth proportional to 218.28, 325.36 and 211.80 is: 315.70

Step by Step Solution

  1. Step 1: Write the proportion equation
    218.28 : 325.36 = 211.80 : x
  2. Step 2: Convert to fraction form
    218.28/325.36 = 211.80/x
  3. Step 3: Cross multiply
    218.28x = 325.36 × 211.80
  4. Step 4: Simplify right side
    218.28x = 68,911.25
  5. Step 5: Solve for x
    x = 68,911.25/218.28
  6. Step 6: Final answer
    x = 315.70

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.