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Finding the Fourth Proportional to 312.54, 428.84 and 309.64

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Solution

The fourth proportional to 312.54, 428.84 and 309.64 is: 424.86

Step by Step Solution

  1. Step 1: Write the proportion equation
    312.54 : 428.84 = 309.64 : x
  2. Step 2: Convert to fraction form
    312.54/428.84 = 309.64/x
  3. Step 3: Cross multiply
    312.54x = 428.84 × 309.64
  4. Step 4: Simplify right side
    312.54x = 132,786.02
  5. Step 5: Solve for x
    x = 132,786.02/312.54
  6. Step 6: Final answer
    x = 424.86

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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.