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Finding the Fourth Proportional to 211.20, 319.20 and 211.20

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Solution

The fourth proportional to 211.20, 319.20 and 211.20 is: 319.20

Step by Step Solution

  1. Step 1: Write the proportion equation
    211.20 : 319.20 = 211.20 : x
  2. Step 2: Convert to fraction form
    211.20/319.20 = 211.20/x
  3. Step 3: Cross multiply
    211.20x = 319.20 × 211.20
  4. Step 4: Simplify right side
    211.20x = 67,415.04
  5. Step 5: Solve for x
    x = 67,415.04/211.20
  6. Step 6: Final answer
    x = 319.20

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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.