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Finding the Fourth Proportional to 28.78, 39.69 and 28.33

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Solution

The fourth proportional to 28.78, 39.69 and 28.33 is: 39.07

Step by Step Solution

  1. Step 1: Write the proportion equation
    28.78 : 39.69 = 28.33 : x
  2. Step 2: Convert to fraction form
    28.78/39.69 = 28.33/x
  3. Step 3: Cross multiply
    28.78x = 39.69 × 28.33
  4. Step 4: Simplify right side
    28.78x = 1,124.32
  5. Step 5: Solve for x
    x = 1,124.32/28.78
  6. Step 6: Final answer
    x = 39.07

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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.