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Finding the Fourth Proportional to 399.48, 551.08 and 288.76

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Solution

The fourth proportional to 399.48, 551.08 and 288.76 is: 398.34

Step by Step Solution

  1. Step 1: Write the proportion equation
    399.48 : 551.08 = 288.76 : x
  2. Step 2: Convert to fraction form
    399.48/551.08 = 288.76/x
  3. Step 3: Cross multiply
    399.48x = 551.08 × 288.76
  4. Step 4: Simplify right side
    399.48x = 159,129.86
  5. Step 5: Solve for x
    x = 159,129.86/399.48
  6. Step 6: Final answer
    x = 398.34

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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.