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Finding the Fourth Proportional to 93.84, 139.94 and 78.72

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Solution

The fourth proportional to 93.84, 139.94 and 78.72 is: 117.39

Step by Step Solution

  1. Step 1: Write the proportion equation
    93.84 : 139.94 = 78.72 : x
  2. Step 2: Convert to fraction form
    93.84/139.94 = 78.72/x
  3. Step 3: Cross multiply
    93.84x = 139.94 × 78.72
  4. Step 4: Simplify right side
    93.84x = 11,015.68
  5. Step 5: Solve for x
    x = 11,015.68/93.84
  6. Step 6: Final answer
    x = 117.39

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.