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Finding the Fourth Proportional to 305.76, 421.84 and 189.28

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Solution

The fourth proportional to 305.76, 421.84 and 189.28 is: 261.14

Step by Step Solution

  1. Step 1: Write the proportion equation
    305.76 : 421.84 = 189.28 : x
  2. Step 2: Convert to fraction form
    305.76/421.84 = 189.28/x
  3. Step 3: Cross multiply
    305.76x = 421.84 × 189.28
  4. Step 4: Simplify right side
    305.76x = 79,845.88
  5. Step 5: Solve for x
    x = 79,845.88/305.76
  6. Step 6: Final answer
    x = 261.14

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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.