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Finding the Third Proportional to 311 and 428.50

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Solution

The third proportional to 311 and 428.50 is: 590.39

Step by Step Solution

  1. Step 1: Write the proportion equation
    311 : 428.50 = 428.50 : x
  2. Step 2: Convert to fraction form
    311/428.50 = 428.50/x
  3. Step 3: Cross multiply
    311x = 428.50 × 428.50
  4. Step 4: Simplify right side
    311x = 183,612.25
  5. Step 5: Solve for x
    x = 183,612.25/311
  6. Step 6: Final answer
    x = 590.39

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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.