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Finding the Fourth Proportional to 499.69, 689.29 and 289.79

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Solution

The fourth proportional to 499.69, 689.29 and 289.79 is: 399.75

Step by Step Solution

  1. Step 1: Write the proportion equation
    499.69 : 689.29 = 289.79 : x
  2. Step 2: Convert to fraction form
    499.69/689.29 = 289.79/x
  3. Step 3: Cross multiply
    499.69x = 689.29 × 289.79
  4. Step 4: Simplify right side
    499.69x = 199,749.35
  5. Step 5: Solve for x
    x = 199,749.35/499.69
  6. Step 6: Final answer
    x = 399.75

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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.