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Finding the Fourth Proportional to 74.80, 111.90 and 65.80

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Solution

The fourth proportional to 74.80, 111.90 and 65.80 is: 98.44

Step by Step Solution

  1. Step 1: Write the proportion equation
    74.80 : 111.90 = 65.80 : x
  2. Step 2: Convert to fraction form
    74.80/111.90 = 65.80/x
  3. Step 3: Cross multiply
    74.80x = 111.90 × 65.80
  4. Step 4: Simplify right side
    74.80x = 7,363.02
  5. Step 5: Solve for x
    x = 7,363.02/74.80
  6. Step 6: Final answer
    x = 98.44

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.