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Finding the Fourth Proportional to 121.90, 182.98 and 67.78

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Solution

The fourth proportional to 121.90, 182.98 and 67.78 is: 101.74

Step by Step Solution

  1. Step 1: Write the proportion equation
    121.90 : 182.98 = 67.78 : x
  2. Step 2: Convert to fraction form
    121.90/182.98 = 67.78/x
  3. Step 3: Cross multiply
    121.90x = 182.98 × 67.78
  4. Step 4: Simplify right side
    121.90x = 12,402.38
  5. Step 5: Solve for x
    x = 12,402.38/121.90
  6. Step 6: Final answer
    x = 101.74

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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.