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Finding the Fourth Proportional to 211.58, 317.36 and 81.62

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Solution

The fourth proportional to 211.58, 317.36 and 81.62 is: 122.42

Step by Step Solution

  1. Step 1: Write the proportion equation
    211.58 : 317.36 = 81.62 : x
  2. Step 2: Convert to fraction form
    211.58/317.36 = 81.62/x
  3. Step 3: Cross multiply
    211.58x = 317.36 × 81.62
  4. Step 4: Simplify right side
    211.58x = 25,901.54
  5. Step 5: Solve for x
    x = 25,901.54/211.58
  6. Step 6: Final answer
    x = 122.42

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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.