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Finding the Fourth Proportional to 30.12, 41.60 and 20.40

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Solution

The fourth proportional to 30.12, 41.60 and 20.40 is: 28.18

Step by Step Solution

  1. Step 1: Write the proportion equation
    30.12 : 41.60 = 20.40 : x
  2. Step 2: Convert to fraction form
    30.12/41.60 = 20.40/x
  3. Step 3: Cross multiply
    30.12x = 41.60 × 20.40
  4. Step 4: Simplify right side
    30.12x = 848.64
  5. Step 5: Solve for x
    x = 848.64/30.12
  6. Step 6: Final answer
    x = 28.18

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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.