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Finding the Fourth Proportional to 130.39, 180 and 86.20

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Solution

The fourth proportional to 130.39, 180 and 86.20 is: 119.00

Step by Step Solution

  1. Step 1: Write the proportion equation
    130.39 : 180 = 86.20 : x
  2. Step 2: Convert to fraction form
    130.39/180 = 86.20/x
  3. Step 3: Cross multiply
    130.39x = 180 × 86.20
  4. Step 4: Simplify right side
    130.39x = 15,515.55
  5. Step 5: Solve for x
    x = 15,515.55/130.39
  6. Step 6: Final answer
    x = 119.00

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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.