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Finding the Fourth Proportional to 120.64, 180.72 and 55.55

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Solution

The fourth proportional to 120.64, 180.72 and 55.55 is: 83.21

Step by Step Solution

  1. Step 1: Write the proportion equation
    120.64 : 180.72 = 55.55 : x
  2. Step 2: Convert to fraction form
    120.64/180.72 = 55.55/x
  3. Step 3: Cross multiply
    120.64x = 180.72 × 55.55
  4. Step 4: Simplify right side
    120.64x = 10,038.27
  5. Step 5: Solve for x
    x = 10,038.27/120.64
  6. Step 6: Final answer
    x = 83.21

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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.