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Finding the Fourth Proportional to 117.70, 162.39 and 77.80

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Solution

The fourth proportional to 117.70, 162.39 and 77.80 is: 107.34

Step by Step Solution

  1. Step 1: Write the proportion equation
    117.70 : 162.39 = 77.80 : x
  2. Step 2: Convert to fraction form
    117.70/162.39 = 77.80/x
  3. Step 3: Cross multiply
    117.70x = 162.39 × 77.80
  4. Step 4: Simplify right side
    117.70x = 12,633.94
  5. Step 5: Solve for x
    x = 12,633.94/117.70
  6. Step 6: Final answer
    x = 107.34

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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.