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Finding the Fourth Proportional to 668.78, 1,003.01 and 339.50

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Solution

The fourth proportional to 668.78, 1,003.01 and 339.50 is: 509.18

Step by Step Solution

  1. Step 1: Write the proportion equation
    668.78 : 1,003.01 = 339.50 : x
  2. Step 2: Convert to fraction form
    668.78/1,003.01 = 339.50/x
  3. Step 3: Cross multiply
    668.78x = 1,003.01 × 339.50
  4. Step 4: Simplify right side
    668.78x = 340,525.25
  5. Step 5: Solve for x
    x = 340,525.25/668.78
  6. Step 6: Final answer
    x = 509.18

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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.