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Finding the Fourth Proportional to 130.78, 196.19 and 39.47

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Solution

The fourth proportional to 130.78, 196.19 and 39.47 is: 59.21

Step by Step Solution

  1. Step 1: Write the proportion equation
    130.78 : 196.19 = 39.47 : x
  2. Step 2: Convert to fraction form
    130.78/196.19 = 39.47/x
  3. Step 3: Cross multiply
    130.78x = 196.19 × 39.47
  4. Step 4: Simplify right side
    130.78x = 7,742.74
  5. Step 5: Solve for x
    x = 7,742.74/130.78
  6. Step 6: Final answer
    x = 59.21

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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.