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Finding the Fourth Proportional to 80.16, 120.15 and 31.39

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Solution

The fourth proportional to 80.16, 120.15 and 31.39 is: 47.05

Step by Step Solution

  1. Step 1: Write the proportion equation
    80.16 : 120.15 = 31.39 : x
  2. Step 2: Convert to fraction form
    80.16/120.15 = 31.39/x
  3. Step 3: Cross multiply
    80.16x = 120.15 × 31.39
  4. Step 4: Simplify right side
    80.16x = 3,771.51
  5. Step 5: Solve for x
    x = 3,771.51/80.16
  6. Step 6: Final answer
    x = 47.05

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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.