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Finding the Fourth Proportional to 145.38, 217.74 and 76.80

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Solution

The fourth proportional to 145.38, 217.74 and 76.80 is: 115.03

Step by Step Solution

  1. Step 1: Write the proportion equation
    145.38 : 217.74 = 76.80 : x
  2. Step 2: Convert to fraction form
    145.38/217.74 = 76.80/x
  3. Step 3: Cross multiply
    145.38x = 217.74 × 76.80
  4. Step 4: Simplify right side
    145.38x = 16,722.43
  5. Step 5: Solve for x
    x = 16,722.43/145.38
  6. Step 6: Final answer
    x = 115.03

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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.