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Finding the Fourth Proportional to 756.70, 1,133.70 and 640.60

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Solution

The fourth proportional to 756.70, 1,133.70 and 640.60 is: 959.76

Step by Step Solution

  1. Step 1: Write the proportion equation
    756.70 : 1,133.70 = 640.60 : x
  2. Step 2: Convert to fraction form
    756.70/1,133.70 = 640.60/x
  3. Step 3: Cross multiply
    756.70x = 1,133.70 × 640.60
  4. Step 4: Simplify right side
    756.70x = 726,248.22
  5. Step 5: Solve for x
    x = 726,248.22/756.70
  6. Step 6: Final answer
    x = 959.76

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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.