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Finding the Fourth Proportional to 130.98, 180.78 and 86.75

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Solution

The fourth proportional to 130.98, 180.78 and 86.75 is: 119.73

Step by Step Solution

  1. Step 1: Write the proportion equation
    130.98 : 180.78 = 86.75 : x
  2. Step 2: Convert to fraction form
    130.98/180.78 = 86.75/x
  3. Step 3: Cross multiply
    130.98x = 180.78 × 86.75
  4. Step 4: Simplify right side
    130.98x = 15,681.76
  5. Step 5: Solve for x
    x = 15,681.76/130.98
  6. Step 6: Final answer
    x = 119.73

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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.