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Finding the Fourth Proportional to 211.20, 307.20 and 211.20

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Solution

The fourth proportional to 211.20, 307.20 and 211.20 is: 307.20

Step by Step Solution

  1. Step 1: Write the proportion equation
    211.20 : 307.20 = 211.20 : x
  2. Step 2: Convert to fraction form
    211.20/307.20 = 211.20/x
  3. Step 3: Cross multiply
    211.20x = 307.20 × 211.20
  4. Step 4: Simplify right side
    211.20x = 64,880.64
  5. Step 5: Solve for x
    x = 64,880.64/211.20
  6. Step 6: Final answer
    x = 307.20

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Why These Related Problems?

These problems maintain the same ratio (1.45) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.