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Finding the Fourth Proportional to 928.64, 1,386.20 and 819.30

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Solution

The fourth proportional to 928.64, 1,386.20 and 819.30 is: 1,222.99

Step by Step Solution

  1. Step 1: Write the proportion equation
    928.64 : 1,386.20 = 819.30 : x
  2. Step 2: Convert to fraction form
    928.64/1,386.20 = 819.30/x
  3. Step 3: Cross multiply
    928.64x = 1,386.20 × 819.30
  4. Step 4: Simplify right side
    928.64x = 1,135,713.66
  5. Step 5: Solve for x
    x = 1,135,713.66/928.64
  6. Step 6: Final answer
    x = 1,222.99

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.