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Finding the Fourth Proportional to 949.20, 1,423.12 and 640.28

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Solution

The fourth proportional to 949.20, 1,423.12 and 640.28 is: 959.96

Step by Step Solution

  1. Step 1: Write the proportion equation
    949.20 : 1,423.12 = 640.28 : x
  2. Step 2: Convert to fraction form
    949.20/1,423.12 = 640.28/x
  3. Step 3: Cross multiply
    949.20x = 1,423.12 × 640.28
  4. Step 4: Simplify right side
    949.20x = 911,192.07
  5. Step 5: Solve for x
    x = 911,192.07/949.20
  6. Step 6: Final answer
    x = 959.96

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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.