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Finding the Fourth Proportional to 305.70, 421.89 and 189.25

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Solution

The fourth proportional to 305.70, 421.89 and 189.25 is: 261.18

Step by Step Solution

  1. Step 1: Write the proportion equation
    305.70 : 421.89 = 189.25 : x
  2. Step 2: Convert to fraction form
    305.70/421.89 = 189.25/x
  3. Step 3: Cross multiply
    305.70x = 421.89 × 189.25
  4. Step 4: Simplify right side
    305.70x = 79,842.68
  5. Step 5: Solve for x
    x = 79,842.68/305.70
  6. Step 6: Final answer
    x = 261.18

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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.