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Finding the Fourth Proportional to 309.70, 427.21 and 235.90

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Solution

The fourth proportional to 309.70, 427.21 and 235.90 is: 325.41

Step by Step Solution

  1. Step 1: Write the proportion equation
    309.70 : 427.21 = 235.90 : x
  2. Step 2: Convert to fraction form
    309.70/427.21 = 235.90/x
  3. Step 3: Cross multiply
    309.70x = 427.21 × 235.90
  4. Step 4: Simplify right side
    309.70x = 100,778.84
  5. Step 5: Solve for x
    x = 100,778.84/309.70
  6. Step 6: Final answer
    x = 325.41

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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.