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Finding the Fourth Proportional to 21.88, 32.68 and 21.24

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Solution

The fourth proportional to 21.88, 32.68 and 21.24 is: 31.72

Step by Step Solution

  1. Step 1: Write the proportion equation
    21.88 : 32.68 = 21.24 : x
  2. Step 2: Convert to fraction form
    21.88/32.68 = 21.24/x
  3. Step 3: Cross multiply
    21.88x = 32.68 × 21.24
  4. Step 4: Simplify right side
    21.88x = 694.12
  5. Step 5: Solve for x
    x = 694.12/21.88
  6. Step 6: Final answer
    x = 31.72

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.