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Finding the Fourth Proportional to 130.63, 180.21 and 81.42

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Solution

The fourth proportional to 130.63, 180.21 and 81.42 is: 112.32

Step by Step Solution

  1. Step 1: Write the proportion equation
    130.63 : 180.21 = 81.42 : x
  2. Step 2: Convert to fraction form
    130.63/180.21 = 81.42/x
  3. Step 3: Cross multiply
    130.63x = 180.21 × 81.42
  4. Step 4: Simplify right side
    130.63x = 14,672.70
  5. Step 5: Solve for x
    x = 14,672.70/130.63
  6. Step 6: Final answer
    x = 112.32

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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.