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Finding the Fourth Proportional to 78.08, 117.60 and 73.92

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Solution

The fourth proportional to 78.08, 117.60 and 73.92 is: 111.33

Step by Step Solution

  1. Step 1: Write the proportion equation
    78.08 : 117.60 = 73.92 : x
  2. Step 2: Convert to fraction form
    78.08/117.60 = 73.92/x
  3. Step 3: Cross multiply
    78.08x = 117.60 × 73.92
  4. Step 4: Simplify right side
    78.08x = 8,692.99
  5. Step 5: Solve for x
    x = 8,692.99/78.08
  6. Step 6: Final answer
    x = 111.33

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Why These Related Problems?

These problems maintain the same ratio (1.51) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.