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Finding the Fourth Proportional to 311.22, 428.94 and 303.12

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Solution

The fourth proportional to 311.22, 428.94 and 303.12 is: 417.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    311.22 : 428.94 = 303.12 : x
  2. Step 2: Convert to fraction form
    311.22/428.94 = 303.12/x
  3. Step 3: Cross multiply
    311.22x = 428.94 × 303.12
  4. Step 4: Simplify right side
    311.22x = 130,020.29
  5. Step 5: Solve for x
    x = 130,020.29/311.22
  6. Step 6: Final answer
    x = 417.78

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.