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Finding the Fourth Proportional to 399.58, 551.54 and 288.81

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Solution

The fourth proportional to 399.58, 551.54 and 288.81 is: 398.65

Step by Step Solution

  1. Step 1: Write the proportion equation
    399.58 : 551.54 = 288.81 : x
  2. Step 2: Convert to fraction form
    399.58/551.54 = 288.81/x
  3. Step 3: Cross multiply
    399.58x = 551.54 × 288.81
  4. Step 4: Simplify right side
    399.58x = 159,290.99
  5. Step 5: Solve for x
    x = 159,290.99/399.58
  6. Step 6: Final answer
    x = 398.65

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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.