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Finding the Fourth Proportional to 305.78, 421.97 and 165.90

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Solution

The fourth proportional to 305.78, 421.97 and 165.90 is: 228.93

Step by Step Solution

  1. Step 1: Write the proportion equation
    305.78 : 421.97 = 165.90 : x
  2. Step 2: Convert to fraction form
    305.78/421.97 = 165.90/x
  3. Step 3: Cross multiply
    305.78x = 421.97 × 165.90
  4. Step 4: Simplify right side
    305.78x = 70,002.30
  5. Step 5: Solve for x
    x = 70,002.30/305.78
  6. Step 6: Final answer
    x = 228.93

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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.