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Finding the Fourth Proportional to 80.58, 120.40 and 65.96

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Solution

The fourth proportional to 80.58, 120.40 and 65.96 is: 98.56

Step by Step Solution

  1. Step 1: Write the proportion equation
    80.58 : 120.40 = 65.96 : x
  2. Step 2: Convert to fraction form
    80.58/120.40 = 65.96/x
  3. Step 3: Cross multiply
    80.58x = 120.40 × 65.96
  4. Step 4: Simplify right side
    80.58x = 7,941.58
  5. Step 5: Solve for x
    x = 7,941.58/80.58
  6. Step 6: Final answer
    x = 98.56

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.