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Finding the Fourth Proportional to 74.40, 111.61 and 20.30

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Solution

The fourth proportional to 74.40, 111.61 and 20.30 is: 30.45

Step by Step Solution

  1. Step 1: Write the proportion equation
    74.40 : 111.61 = 20.30 : x
  2. Step 2: Convert to fraction form
    74.40/111.61 = 20.30/x
  3. Step 3: Cross multiply
    74.40x = 111.61 × 20.30
  4. Step 4: Simplify right side
    74.40x = 2,265.49
  5. Step 5: Solve for x
    x = 2,265.49/74.40
  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.