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Finding the Fourth Proportional to 288.05, 397.76 and 209.81

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Solution

The fourth proportional to 288.05, 397.76 and 209.81 is: 289.72

Step by Step Solution

  1. Step 1: Write the proportion equation
    288.05 : 397.76 = 209.81 : x
  2. Step 2: Convert to fraction form
    288.05/397.76 = 209.81/x
  3. Step 3: Cross multiply
    288.05x = 397.76 × 209.81
  4. Step 4: Simplify right side
    288.05x = 83,450.99
  5. Step 5: Solve for x
    x = 83,450.99/288.05
  6. Step 6: Final answer
    x = 289.72

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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.