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Finding the Fourth Proportional to 80.30, 120.50 and 39.72

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Solution

The fourth proportional to 80.30, 120.50 and 39.72 is: 59.60

Step by Step Solution

  1. Step 1: Write the proportion equation
    80.30 : 120.50 = 39.72 : x
  2. Step 2: Convert to fraction form
    80.30/120.50 = 39.72/x
  3. Step 3: Cross multiply
    80.30x = 120.50 × 39.72
  4. Step 4: Simplify right side
    80.30x = 4,786.26
  5. Step 5: Solve for x
    x = 4,786.26/80.30
  6. Step 6: Final answer
    x = 59.60

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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.