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Finding the Fourth Proportional to 928.21, 1,392.38 and 278.94

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Solution

The fourth proportional to 928.21, 1,392.38 and 278.94 is: 418.43

Step by Step Solution

  1. Step 1: Write the proportion equation
    928.21 : 1,392.38 = 278.94 : x
  2. Step 2: Convert to fraction form
    928.21/1,392.38 = 278.94/x
  3. Step 3: Cross multiply
    928.21x = 1,392.38 × 278.94
  4. Step 4: Simplify right side
    928.21x = 388,390.48
  5. Step 5: Solve for x
    x = 388,390.48/928.21
  6. Step 6: Final answer
    x = 418.43

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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.