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Finding the Fourth Proportional to 123.84, 185.79 and 78.13

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Solution

The fourth proportional to 123.84, 185.79 and 78.13 is: 117.21

Step by Step Solution

  1. Step 1: Write the proportion equation
    123.84 : 185.79 = 78.13 : x
  2. Step 2: Convert to fraction form
    123.84/185.79 = 78.13/x
  3. Step 3: Cross multiply
    123.84x = 185.79 × 78.13
  4. Step 4: Simplify right side
    123.84x = 14,515.77
  5. Step 5: Solve for x
    x = 14,515.77/123.84
  6. Step 6: Final answer
    x = 117.21

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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.