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Finding the Fourth Proportional to 399.51, 551.39 and 289.49

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Solution

The fourth proportional to 399.51, 551.39 and 289.49 is: 399.53

Step by Step Solution

  1. Step 1: Write the proportion equation
    399.51 : 551.39 = 289.49 : x
  2. Step 2: Convert to fraction form
    399.51/551.39 = 289.49/x
  3. Step 3: Cross multiply
    399.51x = 551.39 × 289.49
  4. Step 4: Simplify right side
    399.51x = 159,617.69
  5. Step 5: Solve for x
    x = 159,617.69/399.51
  6. Step 6: Final answer
    x = 399.53

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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.