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Finding the Fourth Proportional to 22.30, 30.71 and 21.42

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Solution

The fourth proportional to 22.30, 30.71 and 21.42 is: 29.50

Step by Step Solution

  1. Step 1: Write the proportion equation
    22.30 : 30.71 = 21.42 : x
  2. Step 2: Convert to fraction form
    22.30/30.71 = 21.42/x
  3. Step 3: Cross multiply
    22.30x = 30.71 × 21.42
  4. Step 4: Simplify right side
    22.30x = 657.86
  5. Step 5: Solve for x
    x = 657.86/22.30
  6. Step 6: Final answer
    x = 29.50

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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.