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Finding the Fourth Proportional to 27.88, 38.47 and 21.42

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Solution

The fourth proportional to 27.88, 38.47 and 21.42 is: 29.56

Step by Step Solution

  1. Step 1: Write the proportion equation
    27.88 : 38.47 = 21.42 : x
  2. Step 2: Convert to fraction form
    27.88/38.47 = 21.42/x
  3. Step 3: Cross multiply
    27.88x = 38.47 × 21.42
  4. Step 4: Simplify right side
    27.88x = 824.03
  5. Step 5: Solve for x
    x = 824.03/27.88
  6. Step 6: Final answer
    x = 29.56

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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.