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Finding the Fourth Proportional to 312.23, 428.19 and 308.63

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Solution

The fourth proportional to 312.23, 428.19 and 308.63 is: 423.25

Step by Step Solution

  1. Step 1: Write the proportion equation
    312.23 : 428.19 = 308.63 : x
  2. Step 2: Convert to fraction form
    312.23/428.19 = 308.63/x
  3. Step 3: Cross multiply
    312.23x = 428.19 × 308.63
  4. Step 4: Simplify right side
    312.23x = 132,150.14
  5. Step 5: Solve for x
    x = 132,150.14/312.23
  6. Step 6: Final answer
    x = 423.25

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Why These Related Problems?

These problems maintain the same ratio (1.37) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.