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Finding the Fourth Proportional to 29.78, 40.88 and 28.46

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Solution

The fourth proportional to 29.78, 40.88 and 28.46 is: 39.08

Step by Step Solution

  1. Step 1: Write the proportion equation
    29.78 : 40.88 = 28.46 : x
  2. Step 2: Convert to fraction form
    29.78/40.88 = 28.46/x
  3. Step 3: Cross multiply
    29.78x = 40.88 × 28.46
  4. Step 4: Simplify right side
    29.78x = 1,163.62
  5. Step 5: Solve for x
    x = 1,163.62/29.78
  6. Step 6: Final answer
    x = 39.08

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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.