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Finding the Fourth Proportional to 117.15, 161.58 and 77.79

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Solution

The fourth proportional to 117.15, 161.58 and 77.79 is: 107.29

Step by Step Solution

  1. Step 1: Write the proportion equation
    117.15 : 161.58 = 77.79 : x
  2. Step 2: Convert to fraction form
    117.15/161.58 = 77.79/x
  3. Step 3: Cross multiply
    117.15x = 161.58 × 77.79
  4. Step 4: Simplify right side
    117.15x = 12,569.31
  5. Step 5: Solve for x
    x = 12,569.31/117.15
  6. Step 6: Final answer
    x = 107.29

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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.