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Finding the Fourth Proportional to 305.51, 421.70 and 238.95

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Solution

The fourth proportional to 305.51, 421.70 and 238.95 is: 329.83

Step by Step Solution

  1. Step 1: Write the proportion equation
    305.51 : 421.70 = 238.95 : x
  2. Step 2: Convert to fraction form
    305.51/421.70 = 238.95/x
  3. Step 3: Cross multiply
    305.51x = 421.70 × 238.95
  4. Step 4: Simplify right side
    305.51x = 100,764.02
  5. Step 5: Solve for x
    x = 100,764.02/305.51
  6. Step 6: Final answer
    x = 329.83

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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.