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Finding the Fourth Proportional to 27.81, 38.35 and 21.23

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Solution

The fourth proportional to 27.81, 38.35 and 21.23 is: 29.28

Step by Step Solution

  1. Step 1: Write the proportion equation
    27.81 : 38.35 = 21.23 : x
  2. Step 2: Convert to fraction form
    27.81/38.35 = 21.23/x
  3. Step 3: Cross multiply
    27.81x = 38.35 × 21.23
  4. Step 4: Simplify right side
    27.81x = 814.17
  5. Step 5: Solve for x
    x = 814.17/27.81
  6. Step 6: Final answer
    x = 29.28

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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.