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Finding the Fourth Proportional to 121.98, 182.18 and 105.78

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Solution

The fourth proportional to 121.98, 182.18 and 105.78 is: 157.98

Step by Step Solution

  1. Step 1: Write the proportion equation
    121.98 : 182.18 = 105.78 : x
  2. Step 2: Convert to fraction form
    121.98/182.18 = 105.78/x
  3. Step 3: Cross multiply
    121.98x = 182.18 × 105.78
  4. Step 4: Simplify right side
    121.98x = 19,271.00
  5. Step 5: Solve for x
    x = 19,271.00/121.98
  6. Step 6: Final answer
    x = 157.98

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.