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Finding the Fourth Proportional to 30.80, 42.38 and 25.94

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Solution

The fourth proportional to 30.80, 42.38 and 25.94 is: 35.69

Step by Step Solution

  1. Step 1: Write the proportion equation
    30.80 : 42.38 = 25.94 : x
  2. Step 2: Convert to fraction form
    30.80/42.38 = 25.94/x
  3. Step 3: Cross multiply
    30.80x = 42.38 × 25.94
  4. Step 4: Simplify right side
    30.80x = 1,099.34
  5. Step 5: Solve for x
    x = 1,099.34/30.80
  6. Step 6: Final answer
    x = 35.69

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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.