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Finding the Fourth Proportional to 928.20, 1,280.64 and 578.64

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Solution

The fourth proportional to 928.20, 1,280.64 and 578.64 is: 798.35

Step by Step Solution

  1. Step 1: Write the proportion equation
    928.20 : 1,280.64 = 578.64 : x
  2. Step 2: Convert to fraction form
    928.20/1,280.64 = 578.64/x
  3. Step 3: Cross multiply
    928.20x = 1,280.64 × 578.64
  4. Step 4: Simplify right side
    928.20x = 741,029.53
  5. Step 5: Solve for x
    x = 741,029.53/928.20
  6. Step 6: Final answer
    x = 798.35

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.