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Finding the Fourth Proportional to 38.90, 53.68 and 25.78

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Solution

The fourth proportional to 38.90, 53.68 and 25.78 is: 35.58

Step by Step Solution

  1. Step 1: Write the proportion equation
    38.90 : 53.68 = 25.78 : x
  2. Step 2: Convert to fraction form
    38.90/53.68 = 25.78/x
  3. Step 3: Cross multiply
    38.90x = 53.68 × 25.78
  4. Step 4: Simplify right side
    38.90x = 1,383.87
  5. Step 5: Solve for x
    x = 1,383.87/38.90
  6. Step 6: Final answer
    x = 35.58

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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.