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Finding the Fourth Proportional to 28.81, 42.96 and 28.78

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Solution

The fourth proportional to 28.81, 42.96 and 28.78 is: 42.92

Step by Step Solution

  1. Step 1: Write the proportion equation
    28.81 : 42.96 = 28.78 : x
  2. Step 2: Convert to fraction form
    28.81/42.96 = 28.78/x
  3. Step 3: Cross multiply
    28.81x = 42.96 × 28.78
  4. Step 4: Simplify right side
    28.81x = 1,236.39
  5. Step 5: Solve for x
    x = 1,236.39/28.81
  6. Step 6: Final answer
    x = 42.92

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.