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Finding the Fourth Proportional to 130.40, 180.08 and 81.32

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Solution

The fourth proportional to 130.40, 180.08 and 81.32 is: 112.30

Step by Step Solution

  1. Step 1: Write the proportion equation
    130.40 : 180.08 = 81.32 : x
  2. Step 2: Convert to fraction form
    130.40/180.08 = 81.32/x
  3. Step 3: Cross multiply
    130.40x = 180.08 × 81.32
  4. Step 4: Simplify right side
    130.40x = 14,644.11
  5. Step 5: Solve for x
    x = 14,644.11/130.40
  6. Step 6: Final answer
    x = 112.30

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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.