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Finding the Fourth Proportional to 817.28, 1,225.08 and 427.08

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Solution

The fourth proportional to 817.28, 1,225.08 and 427.08 is: 640.17

Step by Step Solution

  1. Step 1: Write the proportion equation
    817.28 : 1,225.08 = 427.08 : x
  2. Step 2: Convert to fraction form
    817.28/1,225.08 = 427.08/x
  3. Step 3: Cross multiply
    817.28x = 1,225.08 × 427.08
  4. Step 4: Simplify right side
    817.28x = 523,202.11
  5. Step 5: Solve for x
    x = 523,202.11/817.28
  6. Step 6: Final answer
    x = 640.17

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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.