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Finding the Fourth Proportional to 80.10, 120.15 and 56

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Solution

The fourth proportional to 80.10, 120.15 and 56 is: 84.00

Step by Step Solution

  1. Step 1: Write the proportion equation
    80.10 : 120.15 = 56 : x
  2. Step 2: Convert to fraction form
    80.10/120.15 = 56/x
  3. Step 3: Cross multiply
    80.10x = 120.15 × 56
  4. Step 4: Simplify right side
    80.10x = 6,728.40
  5. Step 5: Solve for x
    x = 6,728.40/80.10
  6. Step 6: Final answer
    x = 84.00

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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.