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Finding the Fourth Proportional to 39.81, 55.04 and 30.09

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Solution

The fourth proportional to 39.81, 55.04 and 30.09 is: 41.60

Step by Step Solution

  1. Step 1: Write the proportion equation
    39.81 : 55.04 = 30.09 : x
  2. Step 2: Convert to fraction form
    39.81/55.04 = 30.09/x
  3. Step 3: Cross multiply
    39.81x = 55.04 × 30.09
  4. Step 4: Simplify right side
    39.81x = 1,656.00
  5. Step 5: Solve for x
    x = 1,656.00/39.81
  6. Step 6: Final answer
    x = 41.60

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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.