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Finding the Fourth Proportional to 212.55, 318.83 and 90.73

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Solution

The fourth proportional to 212.55, 318.83 and 90.73 is: 136.10

Step by Step Solution

  1. Step 1: Write the proportion equation
    212.55 : 318.83 = 90.73 : x
  2. Step 2: Convert to fraction form
    212.55/318.83 = 90.73/x
  3. Step 3: Cross multiply
    212.55x = 318.83 × 90.73
  4. Step 4: Simplify right side
    212.55x = 28,927.39
  5. Step 5: Solve for x
    x = 28,927.39/212.55
  6. Step 6: Final answer
    x = 136.10

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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.