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Finding the Fourth Proportional to 399.17, 551.13 and 305.75

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Solution

The fourth proportional to 399.17, 551.13 and 305.75 is: 422.14

Step by Step Solution

  1. Step 1: Write the proportion equation
    399.17 : 551.13 = 305.75 : x
  2. Step 2: Convert to fraction form
    399.17/551.13 = 305.75/x
  3. Step 3: Cross multiply
    399.17x = 551.13 × 305.75
  4. Step 4: Simplify right side
    399.17x = 168,507.23
  5. Step 5: Solve for x
    x = 168,507.23/399.17
  6. Step 6: Final answer
    x = 422.14

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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.