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Finding the Fourth Proportional to 28.77, 39.69 and 20.55

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Solution

The fourth proportional to 28.77, 39.69 and 20.55 is: 28.35

Step by Step Solution

  1. Step 1: Write the proportion equation
    28.77 : 39.69 = 20.55 : x
  2. Step 2: Convert to fraction form
    28.77/39.69 = 20.55/x
  3. Step 3: Cross multiply
    28.77x = 39.69 × 20.55
  4. Step 4: Simplify right side
    28.77x = 815.63
  5. Step 5: Solve for x
    x = 815.63/28.77
  6. Step 6: Final answer
    x = 28.35

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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.