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Finding the Fourth Proportional to 145.28, 217.85 and 76.64

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Solution

The fourth proportional to 145.28, 217.85 and 76.64 is: 114.91

Step by Step Solution

  1. Step 1: Write the proportion equation
    145.28 : 217.85 = 76.64 : x
  2. Step 2: Convert to fraction form
    145.28/217.85 = 76.64/x
  3. Step 3: Cross multiply
    145.28x = 217.85 × 76.64
  4. Step 4: Simplify right side
    145.28x = 16,694.55
  5. Step 5: Solve for x
    x = 16,694.55/145.28
  6. Step 6: Final answer
    x = 114.91

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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.