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Finding the Fourth Proportional to 28.15, 38.78 and 25.57

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Solution

The fourth proportional to 28.15, 38.78 and 25.57 is: 35.22

Step by Step Solution

  1. Step 1: Write the proportion equation
    28.15 : 38.78 = 25.57 : x
  2. Step 2: Convert to fraction form
    28.15/38.78 = 25.57/x
  3. Step 3: Cross multiply
    28.15x = 38.78 × 25.57
  4. Step 4: Simplify right side
    28.15x = 991.40
  5. Step 5: Solve for x
    x = 991.40/28.15
  6. Step 6: Final answer
    x = 35.22

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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.