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Finding the Fourth Proportional to 30.29, 41.78 and 21.11

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Solution

The fourth proportional to 30.29, 41.78 and 21.11 is: 29.11

Step by Step Solution

  1. Step 1: Write the proportion equation
    30.29 : 41.78 = 21.11 : x
  2. Step 2: Convert to fraction form
    30.29/41.78 = 21.11/x
  3. Step 3: Cross multiply
    30.29x = 41.78 × 21.11
  4. Step 4: Simplify right side
    30.29x = 881.87
  5. Step 5: Solve for x
    x = 881.87/30.29
  6. Step 6: Final answer
    x = 29.11

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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.