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Finding the Fourth Proportional to 305.47, 421.31 and 207.05

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Solution

The fourth proportional to 305.47, 421.31 and 207.05 is: 285.57

Step by Step Solution

  1. Step 1: Write the proportion equation
    305.47 : 421.31 = 207.05 : x
  2. Step 2: Convert to fraction form
    305.47/421.31 = 207.05/x
  3. Step 3: Cross multiply
    305.47x = 421.31 × 207.05
  4. Step 4: Simplify right side
    305.47x = 87,231.20
  5. Step 5: Solve for x
    x = 87,231.20/305.47
  6. Step 6: Final answer
    x = 285.57

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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.