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Finding the Fourth Proportional to 21.88, 30.16 and 17.80

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Solution

The fourth proportional to 21.88, 30.16 and 17.80 is: 24.54

Step by Step Solution

  1. Step 1: Write the proportion equation
    21.88 : 30.16 = 17.80 : x
  2. Step 2: Convert to fraction form
    21.88/30.16 = 17.80/x
  3. Step 3: Cross multiply
    21.88x = 30.16 × 17.80
  4. Step 4: Simplify right side
    21.88x = 536.85
  5. Step 5: Solve for x
    x = 536.85/21.88
  6. Step 6: Final answer
    x = 24.54

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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.