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Finding the Fourth Proportional to 21.64, 29.87 and 18.38

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Solution

The fourth proportional to 21.64, 29.87 and 18.38 is: 25.36

Step by Step Solution

  1. Step 1: Write the proportion equation
    21.64 : 29.87 = 18.38 : x
  2. Step 2: Convert to fraction form
    21.64/29.87 = 18.38/x
  3. Step 3: Cross multiply
    21.64x = 29.87 × 18.38
  4. Step 4: Simplify right side
    21.64x = 548.77
  5. Step 5: Solve for x
    x = 548.77/21.64
  6. Step 6: Final answer
    x = 25.36

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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.