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Finding the Fourth Proportional to 212.31, 316.40 and 205.70

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Solution

The fourth proportional to 212.31, 316.40 and 205.70 is: 306.54

Step by Step Solution

  1. Step 1: Write the proportion equation
    212.31 : 316.40 = 205.70 : x
  2. Step 2: Convert to fraction form
    212.31/316.40 = 205.70/x
  3. Step 3: Cross multiply
    212.31x = 316.40 × 205.70
  4. Step 4: Simplify right side
    212.31x = 65,080.87
  5. Step 5: Solve for x
    x = 65,080.87/212.31
  6. Step 6: Final answer
    x = 306.54

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.