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Finding the Fourth Proportional to 499.49, 689.21 and 289.67

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Solution

The fourth proportional to 499.49, 689.21 and 289.67 is: 399.69

Step by Step Solution

  1. Step 1: Write the proportion equation
    499.49 : 689.21 = 289.67 : x
  2. Step 2: Convert to fraction form
    499.49/689.21 = 289.67/x
  3. Step 3: Cross multiply
    499.49x = 689.21 × 289.67
  4. Step 4: Simplify right side
    499.49x = 199,638.57
  5. Step 5: Solve for x
    x = 199,638.57/499.49
  6. Step 6: Final answer
    x = 399.69

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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.