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Finding the Fourth Proportional to 135.79, 187.44 and 121.21

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Solution

The fourth proportional to 135.79, 187.44 and 121.21 is: 167.31

Step by Step Solution

  1. Step 1: Write the proportion equation
    135.79 : 187.44 = 121.21 : x
  2. Step 2: Convert to fraction form
    135.79/187.44 = 121.21/x
  3. Step 3: Cross multiply
    135.79x = 187.44 × 121.21
  4. Step 4: Simplify right side
    135.79x = 22,719.60
  5. Step 5: Solve for x
    x = 22,719.60/135.79
  6. Step 6: Final answer
    x = 167.31

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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.