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Finding the Fourth Proportional to 499.30, 689.10 and 289.50

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Solution

The fourth proportional to 499.30, 689.10 and 289.50 is: 399.55

Step by Step Solution

  1. Step 1: Write the proportion equation
    499.30 : 689.10 = 289.50 : x
  2. Step 2: Convert to fraction form
    499.30/689.10 = 289.50/x
  3. Step 3: Cross multiply
    499.30x = 689.10 × 289.50
  4. Step 4: Simplify right side
    499.30x = 199,494.45
  5. Step 5: Solve for x
    x = 199,494.45/499.30
  6. Step 6: Final answer
    x = 399.55

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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.