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Finding the Fourth Proportional to 754.93, 1,128.75 and 640.72

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Solution

The fourth proportional to 754.93, 1,128.75 and 640.72 is: 957.99

Step by Step Solution

  1. Step 1: Write the proportion equation
    754.93 : 1,128.75 = 640.72 : x
  2. Step 2: Convert to fraction form
    754.93/1,128.75 = 640.72/x
  3. Step 3: Cross multiply
    754.93x = 1,128.75 × 640.72
  4. Step 4: Simplify right side
    754.93x = 723,212.70
  5. Step 5: Solve for x
    x = 723,212.70/754.93
  6. Step 6: Final answer
    x = 957.99

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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.