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Finding the Fourth Proportional to 427.50, 639.99 and 289.62

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Solution

The fourth proportional to 427.50, 639.99 and 289.62 is: 433.58

Step by Step Solution

  1. Step 1: Write the proportion equation
    427.50 : 639.99 = 289.62 : x
  2. Step 2: Convert to fraction form
    427.50/639.99 = 289.62/x
  3. Step 3: Cross multiply
    427.50x = 639.99 × 289.62
  4. Step 4: Simplify right side
    427.50x = 185,353.90
  5. Step 5: Solve for x
    x = 185,353.90/427.50
  6. Step 6: Final answer
    x = 433.58

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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.