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Finding the Fourth Proportional to 39.83, 55.07 and 30.65

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Solution

The fourth proportional to 39.83, 55.07 and 30.65 is: 42.38

Step by Step Solution

  1. Step 1: Write the proportion equation
    39.83 : 55.07 = 30.65 : x
  2. Step 2: Convert to fraction form
    39.83/55.07 = 30.65/x
  3. Step 3: Cross multiply
    39.83x = 55.07 × 30.65
  4. Step 4: Simplify right side
    39.83x = 1,688.18
  5. Step 5: Solve for x
    x = 1,688.18/39.83
  6. Step 6: Final answer
    x = 42.38

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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.