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Finding the Fourth Proportional to 121.52, 167.84 and 99.80

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Solution

The fourth proportional to 121.52, 167.84 and 99.80 is: 137.84

Step by Step Solution

  1. Step 1: Write the proportion equation
    121.52 : 167.84 = 99.80 : x
  2. Step 2: Convert to fraction form
    121.52/167.84 = 99.80/x
  3. Step 3: Cross multiply
    121.52x = 167.84 × 99.80
  4. Step 4: Simplify right side
    121.52x = 16,750.43
  5. Step 5: Solve for x
    x = 16,750.43/121.52
  6. Step 6: Final answer
    x = 137.84

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.