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Finding the Fourth Proportional to 22.38, 30.81 and 21.30

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Solution

The fourth proportional to 22.38, 30.81 and 21.30 is: 29.32

Step by Step Solution

  1. Step 1: Write the proportion equation
    22.38 : 30.81 = 21.30 : x
  2. Step 2: Convert to fraction form
    22.38/30.81 = 21.30/x
  3. Step 3: Cross multiply
    22.38x = 30.81 × 21.30
  4. Step 4: Simplify right side
    22.38x = 656.25
  5. Step 5: Solve for x
    x = 656.25/22.38
  6. Step 6: Final answer
    x = 29.32

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1.5x scale

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.