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Finding the Fourth Proportional to 30.09, 45.11 and 20.31

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Solution

The fourth proportional to 30.09, 45.11 and 20.31 is: 30.45

Step by Step Solution

  1. Step 1: Write the proportion equation
    30.09 : 45.11 = 20.31 : x
  2. Step 2: Convert to fraction form
    30.09/45.11 = 20.31/x
  3. Step 3: Cross multiply
    30.09x = 45.11 × 20.31
  4. Step 4: Simplify right side
    30.09x = 916.18
  5. Step 5: Solve for x
    x = 916.18/30.09
  6. Step 6: Final answer
    x = 30.45

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.