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Finding the Fourth Proportional to 499.40, 689.15 and 289.57

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Solution

The fourth proportional to 499.40, 689.15 and 289.57 is: 399.59

Step by Step Solution

  1. Step 1: Write the proportion equation
    499.40 : 689.15 = 289.57 : x
  2. Step 2: Convert to fraction form
    499.40/689.15 = 289.57/x
  3. Step 3: Cross multiply
    499.40x = 689.15 × 289.57
  4. Step 4: Simplify right side
    499.40x = 199,553.72
  5. Step 5: Solve for x
    x = 199,553.72/499.40
  6. Step 6: Final answer
    x = 399.59

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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.