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Finding the Fourth Proportional to 499.42, 689.30 and 289.72

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Solution

The fourth proportional to 499.42, 689.30 and 289.72 is: 399.87

Step by Step Solution

  1. Step 1: Write the proportion equation
    499.42 : 689.30 = 289.72 : x
  2. Step 2: Convert to fraction form
    499.42/689.30 = 289.72/x
  3. Step 3: Cross multiply
    499.42x = 689.30 × 289.72
  4. Step 4: Simplify right side
    499.42x = 199,704.00
  5. Step 5: Solve for x
    x = 199,704.00/499.42
  6. Step 6: Final answer
    x = 399.87

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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.