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Finding the Fourth Proportional to 679.80, 938.26 and 400.20

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Solution

The fourth proportional to 679.80, 938.26 and 400.20 is: 552.36

Step by Step Solution

  1. Step 1: Write the proportion equation
    679.80 : 938.26 = 400.20 : x
  2. Step 2: Convert to fraction form
    679.80/938.26 = 400.20/x
  3. Step 3: Cross multiply
    679.80x = 938.26 × 400.20
  4. Step 4: Simplify right side
    679.80x = 375,491.65
  5. Step 5: Solve for x
    x = 375,491.65/679.80
  6. Step 6: Final answer
    x = 552.36

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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.