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Finding the Fourth Proportional to 399.42, 551.47 and 306

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Solution

The fourth proportional to 399.42, 551.47 and 306 is: 422.49

Step by Step Solution

  1. Step 1: Write the proportion equation
    399.42 : 551.47 = 306 : x
  2. Step 2: Convert to fraction form
    399.42/551.47 = 306/x
  3. Step 3: Cross multiply
    399.42x = 551.47 × 306
  4. Step 4: Simplify right side
    399.42x = 168,749.82
  5. Step 5: Solve for x
    x = 168,749.82/399.42
  6. Step 6: Final answer
    x = 422.49

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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.