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Finding the Fourth Proportional to 22.29, 30.78 and 15.39

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Solution

The fourth proportional to 22.29, 30.78 and 15.39 is: 21.25

Step by Step Solution

  1. Step 1: Write the proportion equation
    22.29 : 30.78 = 15.39 : x
  2. Step 2: Convert to fraction form
    22.29/30.78 = 15.39/x
  3. Step 3: Cross multiply
    22.29x = 30.78 × 15.39
  4. Step 4: Simplify right side
    22.29x = 473.70
  5. Step 5: Solve for x
    x = 473.70/22.29
  6. Step 6: Final answer
    x = 21.25

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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.