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Finding the Fourth Proportional to 960.40, 1,439.72 and 310.80

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Solution

The fourth proportional to 960.40, 1,439.72 and 310.80 is: 465.92

Step by Step Solution

  1. Step 1: Write the proportion equation
    960.40 : 1,439.72 = 310.80 : x
  2. Step 2: Convert to fraction form
    960.40/1,439.72 = 310.80/x
  3. Step 3: Cross multiply
    960.40x = 1,439.72 × 310.80
  4. Step 4: Simplify right side
    960.40x = 447,464.98
  5. Step 5: Solve for x
    x = 447,464.98/960.40
  6. Step 6: Final answer
    x = 465.92

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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.