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Finding the Fourth Proportional to 39.85, 59.80 and 19.57

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Solution

The fourth proportional to 39.85, 59.80 and 19.57 is: 29.38

Step by Step Solution

  1. Step 1: Write the proportion equation
    39.85 : 59.80 = 19.57 : x
  2. Step 2: Convert to fraction form
    39.85/59.80 = 19.57/x
  3. Step 3: Cross multiply
    39.85x = 59.80 × 19.57
  4. Step 4: Simplify right side
    39.85x = 1,170.48
  5. Step 5: Solve for x
    x = 1,170.48/39.85
  6. Step 6: Final answer
    x = 29.38

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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.