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Finding the Fourth Proportional to 288.86, 399.20 and 218.89

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Solution

The fourth proportional to 288.86, 399.20 and 218.89 is: 302.50

Step by Step Solution

  1. Step 1: Write the proportion equation
    288.86 : 399.20 = 218.89 : x
  2. Step 2: Convert to fraction form
    288.86/399.20 = 218.89/x
  3. Step 3: Cross multiply
    288.86x = 399.20 × 218.89
  4. Step 4: Simplify right side
    288.86x = 87,380.89
  5. Step 5: Solve for x
    x = 87,380.89/288.86
  6. Step 6: Final answer
    x = 302.50

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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.