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Finding the Fourth Proportional to 131.10, 180.72 and 128.67

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Solution

The fourth proportional to 131.10, 180.72 and 128.67 is: 177.37

Step by Step Solution

  1. Step 1: Write the proportion equation
    131.10 : 180.72 = 128.67 : x
  2. Step 2: Convert to fraction form
    131.10/180.72 = 128.67/x
  3. Step 3: Cross multiply
    131.10x = 180.72 × 128.67
  4. Step 4: Simplify right side
    131.10x = 23,253.24
  5. Step 5: Solve for x
    x = 23,253.24/131.10
  6. Step 6: Final answer
    x = 177.37

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.