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Finding the Fourth Proportional to 22.80, 31.51 and 21.56

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Solution

The fourth proportional to 22.80, 31.51 and 21.56 is: 29.79

Step by Step Solution

  1. Step 1: Write the proportion equation
    22.80 : 31.51 = 21.56 : x
  2. Step 2: Convert to fraction form
    22.80/31.51 = 21.56/x
  3. Step 3: Cross multiply
    22.80x = 31.51 × 21.56
  4. Step 4: Simplify right side
    22.80x = 679.22
  5. Step 5: Solve for x
    x = 679.22/22.80
  6. Step 6: Final answer
    x = 29.79

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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.