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Finding the Fourth Proportional to 145.20, 217.71 and 53.79

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Solution

The fourth proportional to 145.20, 217.71 and 53.79 is: 80.65

Step by Step Solution

  1. Step 1: Write the proportion equation
    145.20 : 217.71 = 53.79 : x
  2. Step 2: Convert to fraction form
    145.20/217.71 = 53.79/x
  3. Step 3: Cross multiply
    145.20x = 217.71 × 53.79
  4. Step 4: Simplify right side
    145.20x = 11,710.62
  5. Step 5: Solve for x
    x = 11,710.62/145.20
  6. Step 6: Final answer
    x = 80.65

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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.