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Finding the Fourth Proportional to 130.65, 180.38 and 81.60

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Solution

The fourth proportional to 130.65, 180.38 and 81.60 is: 112.66

Step by Step Solution

  1. Step 1: Write the proportion equation
    130.65 : 180.38 = 81.60 : x
  2. Step 2: Convert to fraction form
    130.65/180.38 = 81.60/x
  3. Step 3: Cross multiply
    130.65x = 180.38 × 81.60
  4. Step 4: Simplify right side
    130.65x = 14,719.01
  5. Step 5: Solve for x
    x = 14,719.01/130.65
  6. Step 6: Final answer
    x = 112.66

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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.