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Finding the Fourth Proportional to 679.86, 938.08 and 400.15

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Solution

The fourth proportional to 679.86, 938.08 and 400.15 is: 552.13

Step by Step Solution

  1. Step 1: Write the proportion equation
    679.86 : 938.08 = 400.15 : x
  2. Step 2: Convert to fraction form
    679.86/938.08 = 400.15/x
  3. Step 3: Cross multiply
    679.86x = 938.08 × 400.15
  4. Step 4: Simplify right side
    679.86x = 375,372.71
  5. Step 5: Solve for x
    x = 375,372.71/679.86
  6. Step 6: Final answer
    x = 552.13

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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.