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Finding the Fourth Proportional to 305.30, 421.37 and 238.78

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Solution

The fourth proportional to 305.30, 421.37 and 238.78 is: 329.56

Step by Step Solution

  1. Step 1: Write the proportion equation
    305.30 : 421.37 = 238.78 : x
  2. Step 2: Convert to fraction form
    305.30/421.37 = 238.78/x
  3. Step 3: Cross multiply
    305.30x = 421.37 × 238.78
  4. Step 4: Simplify right side
    305.30x = 100,613.68
  5. Step 5: Solve for x
    x = 100,613.68/305.30
  6. Step 6: Final answer
    x = 329.56

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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.