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Finding the Fourth Proportional to 668.58, 1,002.18 and 278.79

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Solution

The fourth proportional to 668.58, 1,002.18 and 278.79 is: 417.90

Step by Step Solution

  1. Step 1: Write the proportion equation
    668.58 : 1,002.18 = 278.79 : x
  2. Step 2: Convert to fraction form
    668.58/1,002.18 = 278.79/x
  3. Step 3: Cross multiply
    668.58x = 1,002.18 × 278.79
  4. Step 4: Simplify right side
    668.58x = 279,396.37
  5. Step 5: Solve for x
    x = 279,396.37/668.58
  6. Step 6: Final answer
    x = 417.90

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.