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Finding the Fourth Proportional to 22.35, 30.87 and 21

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Solution

The fourth proportional to 22.35, 30.87 and 21 is: 29.01

Step by Step Solution

  1. Step 1: Write the proportion equation
    22.35 : 30.87 = 21 : x
  2. Step 2: Convert to fraction form
    22.35/30.87 = 21/x
  3. Step 3: Cross multiply
    22.35x = 30.87 × 21
  4. Step 4: Simplify right side
    22.35x = 648.27
  5. Step 5: Solve for x
    x = 648.27/22.35
  6. Step 6: Final answer
    x = 29.01

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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.