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Finding the Fourth Proportional to 938.21, 1,407.02 and 321.80

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Solution

The fourth proportional to 938.21, 1,407.02 and 321.80 is: 482.59

Step by Step Solution

  1. Step 1: Write the proportion equation
    938.21 : 1,407.02 = 321.80 : x
  2. Step 2: Convert to fraction form
    938.21/1,407.02 = 321.80/x
  3. Step 3: Cross multiply
    938.21x = 1,407.02 × 321.80
  4. Step 4: Simplify right side
    938.21x = 452,770.39
  5. Step 5: Solve for x
    x = 452,770.39/938.21
  6. Step 6: Final answer
    x = 482.59

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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.