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Finding the Fourth Proportional to 28.20, 38.64 and 28.08

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Solution

The fourth proportional to 28.20, 38.64 and 28.08 is: 38.48

Step by Step Solution

  1. Step 1: Write the proportion equation
    28.20 : 38.64 = 28.08 : x
  2. Step 2: Convert to fraction form
    28.20/38.64 = 28.08/x
  3. Step 3: Cross multiply
    28.20x = 38.64 × 28.08
  4. Step 4: Simplify right side
    28.20x = 1,085.01
  5. Step 5: Solve for x
    x = 1,085.01/28.20
  6. Step 6: Final answer
    x = 38.48

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Why These Related Problems?

These problems maintain the same ratio (1.37) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.