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Finding the Fourth Proportional to 75.42, 104.09 and 47.80

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Solution

The fourth proportional to 75.42, 104.09 and 47.80 is: 65.97

Step by Step Solution

  1. Step 1: Write the proportion equation
    75.42 : 104.09 = 47.80 : x
  2. Step 2: Convert to fraction form
    75.42/104.09 = 47.80/x
  3. Step 3: Cross multiply
    75.42x = 104.09 × 47.80
  4. Step 4: Simplify right side
    75.42x = 4,975.50
  5. Step 5: Solve for x
    x = 4,975.50/75.42
  6. Step 6: Final answer
    x = 65.97

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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.