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Finding the Fourth Proportional to 305.58, 421.38 and 280.92

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Solution

The fourth proportional to 305.58, 421.38 and 280.92 is: 387.38

Step by Step Solution

  1. Step 1: Write the proportion equation
    305.58 : 421.38 = 280.92 : x
  2. Step 2: Convert to fraction form
    305.58/421.38 = 280.92/x
  3. Step 3: Cross multiply
    305.58x = 421.38 × 280.92
  4. Step 4: Simplify right side
    305.58x = 118,374.07
  5. Step 5: Solve for x
    x = 118,374.07/305.58
  6. Step 6: Final answer
    x = 387.38

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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.