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Finding the Fourth Proportional to 23.13, 31.91 and 21.42

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Solution

The fourth proportional to 23.13, 31.91 and 21.42 is: 29.55

Step by Step Solution

  1. Step 1: Write the proportion equation
    23.13 : 31.91 = 21.42 : x
  2. Step 2: Convert to fraction form
    23.13/31.91 = 21.42/x
  3. Step 3: Cross multiply
    23.13x = 31.91 × 21.42
  4. Step 4: Simplify right side
    23.13x = 683.41
  5. Step 5: Solve for x
    x = 683.41/23.13
  6. Step 6: Final answer
    x = 29.55

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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.