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Finding the Fourth Proportional to 211.17, 316.72 and 81.10

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Solution

The fourth proportional to 211.17, 316.72 and 81.10 is: 121.63

Step by Step Solution

  1. Step 1: Write the proportion equation
    211.17 : 316.72 = 81.10 : x
  2. Step 2: Convert to fraction form
    211.17/316.72 = 81.10/x
  3. Step 3: Cross multiply
    211.17x = 316.72 × 81.10
  4. Step 4: Simplify right side
    211.17x = 25,684.00
  5. Step 5: Solve for x
    x = 25,684.00/211.17
  6. Step 6: Final answer
    x = 121.63

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.