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Finding the Fourth Proportional to 500.75, 690.41 and 389.99

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Solution

The fourth proportional to 500.75, 690.41 and 389.99 is: 537.69

Step by Step Solution

  1. Step 1: Write the proportion equation
    500.75 : 690.41 = 389.99 : x
  2. Step 2: Convert to fraction form
    500.75/690.41 = 389.99/x
  3. Step 3: Cross multiply
    500.75x = 690.41 × 389.99
  4. Step 4: Simplify right side
    500.75x = 269,247.59
  5. Step 5: Solve for x
    x = 269,247.59/500.75
  6. Step 6: Final answer
    x = 537.69

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.