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Finding the Fourth Proportional to 212.34, 318.40 and 80.50

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Solution

The fourth proportional to 212.34, 318.40 and 80.50 is: 120.71

Step by Step Solution

  1. Step 1: Write the proportion equation
    212.34 : 318.40 = 80.50 : x
  2. Step 2: Convert to fraction form
    212.34/318.40 = 80.50/x
  3. Step 3: Cross multiply
    212.34x = 318.40 × 80.50
  4. Step 4: Simplify right side
    212.34x = 25,631.20
  5. Step 5: Solve for x
    x = 25,631.20/212.34
  6. Step 6: Final answer
    x = 120.71

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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.