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Finding the Fourth Proportional to 130.88, 180.60 and 78.42

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Solution

The fourth proportional to 130.88, 180.60 and 78.42 is: 108.21

Step by Step Solution

  1. Step 1: Write the proportion equation
    130.88 : 180.60 = 78.42 : x
  2. Step 2: Convert to fraction form
    130.88/180.60 = 78.42/x
  3. Step 3: Cross multiply
    130.88x = 180.60 × 78.42
  4. Step 4: Simplify right side
    130.88x = 14,162.46
  5. Step 5: Solve for x
    x = 14,162.46/130.88
  6. Step 6: Final answer
    x = 108.21

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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.