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Finding the Fourth Proportional to 30.83, 42.55 and 18.55

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Solution

The fourth proportional to 30.83, 42.55 and 18.55 is: 25.60

Step by Step Solution

  1. Step 1: Write the proportion equation
    30.83 : 42.55 = 18.55 : x
  2. Step 2: Convert to fraction form
    30.83/42.55 = 18.55/x
  3. Step 3: Cross multiply
    30.83x = 42.55 × 18.55
  4. Step 4: Simplify right side
    30.83x = 789.30
  5. Step 5: Solve for x
    x = 789.30/30.83
  6. Step 6: Final answer
    x = 25.60

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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.