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Finding the Fourth Proportional to 305.74, 421.40 and 239.25

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Solution

The fourth proportional to 305.74, 421.40 and 239.25 is: 329.76

Step by Step Solution

  1. Step 1: Write the proportion equation
    305.74 : 421.40 = 239.25 : x
  2. Step 2: Convert to fraction form
    305.74/421.40 = 239.25/x
  3. Step 3: Cross multiply
    305.74x = 421.40 × 239.25
  4. Step 4: Simplify right side
    305.74x = 100,822.13
  5. Step 5: Solve for x
    x = 100,822.13/305.74
  6. Step 6: Final answer
    x = 329.76

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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.