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Finding the Fourth Proportional to 123.81, 185.74 and 42.65

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Solution

The fourth proportional to 123.81, 185.74 and 42.65 is: 63.98

Step by Step Solution

  1. Step 1: Write the proportion equation
    123.81 : 185.74 = 42.65 : x
  2. Step 2: Convert to fraction form
    123.81/185.74 = 42.65/x
  3. Step 3: Cross multiply
    123.81x = 185.74 × 42.65
  4. Step 4: Simplify right side
    123.81x = 7,921.47
  5. Step 5: Solve for x
    x = 7,921.47/123.81
  6. Step 6: Final answer
    x = 63.98

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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.