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Finding the Fourth Proportional to 499.81, 689.65 and 287.09

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Solution

The fourth proportional to 499.81, 689.65 and 287.09 is: 396.13

Step by Step Solution

  1. Step 1: Write the proportion equation
    499.81 : 689.65 = 287.09 : x
  2. Step 2: Convert to fraction form
    499.81/689.65 = 287.09/x
  3. Step 3: Cross multiply
    499.81x = 689.65 × 287.09
  4. Step 4: Simplify right side
    499.81x = 197,988.17
  5. Step 5: Solve for x
    x = 197,988.17/499.81
  6. Step 6: Final answer
    x = 396.13

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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.