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Finding the Fourth Proportional to 305.49, 421.61 and 189.09

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Solution

The fourth proportional to 305.49, 421.61 and 189.09 is: 260.96

Step by Step Solution

  1. Step 1: Write the proportion equation
    305.49 : 421.61 = 189.09 : x
  2. Step 2: Convert to fraction form
    305.49/421.61 = 189.09/x
  3. Step 3: Cross multiply
    305.49x = 421.61 × 189.09
  4. Step 4: Simplify right side
    305.49x = 79,720.60
  5. Step 5: Solve for x
    x = 79,720.60/305.49
  6. Step 6: Final answer
    x = 260.96

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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.