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Finding the Fourth Proportional to 130.89, 196.40 and 66.81

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Solution

The fourth proportional to 130.89, 196.40 and 66.81 is: 100.25

Step by Step Solution

  1. Step 1: Write the proportion equation
    130.89 : 196.40 = 66.81 : x
  2. Step 2: Convert to fraction form
    130.89/196.40 = 66.81/x
  3. Step 3: Cross multiply
    130.89x = 196.40 × 66.81
  4. Step 4: Simplify right side
    130.89x = 13,121.15
  5. Step 5: Solve for x
    x = 13,121.15/130.89
  6. Step 6: Final answer
    x = 100.25

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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.