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Finding the Fourth Proportional to 838.69, 1,256.89 and 399.87

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Solution

The fourth proportional to 838.69, 1,256.89 and 399.87 is: 599.26

Step by Step Solution

  1. Step 1: Write the proportion equation
    838.69 : 1,256.89 = 399.87 : x
  2. Step 2: Convert to fraction form
    838.69/1,256.89 = 399.87/x
  3. Step 3: Cross multiply
    838.69x = 1,256.89 × 399.87
  4. Step 4: Simplify right side
    838.69x = 502,592.60
  5. Step 5: Solve for x
    x = 502,592.60/838.69
  6. Step 6: Final answer
    x = 599.26

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.