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Finding the Fourth Proportional to 169.72, 254.39 and 78.39

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Solution

The fourth proportional to 169.72, 254.39 and 78.39 is: 117.50

Step by Step Solution

  1. Step 1: Write the proportion equation
    169.72 : 254.39 = 78.39 : x
  2. Step 2: Convert to fraction form
    169.72/254.39 = 78.39/x
  3. Step 3: Cross multiply
    169.72x = 254.39 × 78.39
  4. Step 4: Simplify right side
    169.72x = 19,941.63
  5. Step 5: Solve for x
    x = 19,941.63/169.72
  6. Step 6: Final answer
    x = 117.50

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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.