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Finding the Fourth Proportional to 74.80, 111.63 and 68.91

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Solution

The fourth proportional to 74.80, 111.63 and 68.91 is: 102.84

Step by Step Solution

  1. Step 1: Write the proportion equation
    74.80 : 111.63 = 68.91 : x
  2. Step 2: Convert to fraction form
    74.80/111.63 = 68.91/x
  3. Step 3: Cross multiply
    74.80x = 111.63 × 68.91
  4. Step 4: Simplify right side
    74.80x = 7,692.42
  5. Step 5: Solve for x
    x = 7,692.42/74.80
  6. Step 6: Final answer
    x = 102.84

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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.