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Finding the Fourth Proportional to 285.15, 393.28 and 218.79

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Solution

The fourth proportional to 285.15, 393.28 and 218.79 is: 301.76

Step by Step Solution

  1. Step 1: Write the proportion equation
    285.15 : 393.28 = 218.79 : x
  2. Step 2: Convert to fraction form
    285.15/393.28 = 218.79/x
  3. Step 3: Cross multiply
    285.15x = 393.28 × 218.79
  4. Step 4: Simplify right side
    285.15x = 86,045.73
  5. Step 5: Solve for x
    x = 86,045.73/285.15
  6. Step 6: Final answer
    x = 301.76

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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.