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Finding the Fourth Proportional to 221, 305.78 and 189.88

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Solution

The fourth proportional to 221, 305.78 and 189.88 is: 262.72

Step by Step Solution

  1. Step 1: Write the proportion equation
    221 : 305.78 = 189.88 : x
  2. Step 2: Convert to fraction form
    221/305.78 = 189.88/x
  3. Step 3: Cross multiply
    221x = 305.78 × 189.88
  4. Step 4: Simplify right side
    221x = 58,061.51
  5. Step 5: Solve for x
    x = 58,061.51/221
  6. Step 6: Final answer
    x = 262.72

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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.