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Finding the Fourth Proportional to 22.40, 30.89 and 21.21

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Solution

The fourth proportional to 22.40, 30.89 and 21.21 is: 29.25

Step by Step Solution

  1. Step 1: Write the proportion equation
    22.40 : 30.89 = 21.21 : x
  2. Step 2: Convert to fraction form
    22.40/30.89 = 21.21/x
  3. Step 3: Cross multiply
    22.40x = 30.89 × 21.21
  4. Step 4: Simplify right side
    22.40x = 655.07
  5. Step 5: Solve for x
    x = 655.07/22.40
  6. Step 6: Final answer
    x = 29.25

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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.