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Finding the Fourth Proportional to 640, 960.78 and 433.72

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Solution

The fourth proportional to 640, 960.78 and 433.72 is: 651.11

Step by Step Solution

  1. Step 1: Write the proportion equation
    640 : 960.78 = 433.72 : x
  2. Step 2: Convert to fraction form
    640/960.78 = 433.72/x
  3. Step 3: Cross multiply
    640x = 960.78 × 433.72
  4. Step 4: Simplify right side
    640x = 416,709.50
  5. Step 5: Solve for x
    x = 416,709.50/640
  6. Step 6: Final answer
    x = 651.11

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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.