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Finding the Fourth Proportional to 123.75, 185.42 and 78.19

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Solution

The fourth proportional to 123.75, 185.42 and 78.19 is: 117.15

Step by Step Solution

  1. Step 1: Write the proportion equation
    123.75 : 185.42 = 78.19 : x
  2. Step 2: Convert to fraction form
    123.75/185.42 = 78.19/x
  3. Step 3: Cross multiply
    123.75x = 185.42 × 78.19
  4. Step 4: Simplify right side
    123.75x = 14,497.72
  5. Step 5: Solve for x
    x = 14,497.72/123.75
  6. Step 6: Final answer
    x = 117.15

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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.