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Finding the Fourth Proportional to 309.85, 428.72 and 270.60

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Solution

The fourth proportional to 309.85, 428.72 and 270.60 is: 374.41

Step by Step Solution

  1. Step 1: Write the proportion equation
    309.85 : 428.72 = 270.60 : x
  2. Step 2: Convert to fraction form
    309.85/428.72 = 270.60/x
  3. Step 3: Cross multiply
    309.85x = 428.72 × 270.60
  4. Step 4: Simplify right side
    309.85x = 116,011.63
  5. Step 5: Solve for x
    x = 116,011.63/309.85
  6. Step 6: Final answer
    x = 374.41

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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.