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Finding the Fourth Proportional to 960.80, 1,438.80 and 768.80

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Solution

The fourth proportional to 960.80, 1,438.80 and 768.80 is: 1,151.28

Step by Step Solution

  1. Step 1: Write the proportion equation
    960.80 : 1,438.80 = 768.80 : x
  2. Step 2: Convert to fraction form
    960.80/1,438.80 = 768.80/x
  3. Step 3: Cross multiply
    960.80x = 1,438.80 × 768.80
  4. Step 4: Simplify right side
    960.80x = 1,106,149.44
  5. Step 5: Solve for x
    x = 1,106,149.44/960.80
  6. Step 6: Final answer
    x = 1,151.28

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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.