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Finding the Fourth Proportional to 949.50, 1,422.78 and 640.20

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Solution

The fourth proportional to 949.50, 1,422.78 and 640.20 is: 959.31

Step by Step Solution

  1. Step 1: Write the proportion equation
    949.50 : 1,422.78 = 640.20 : x
  2. Step 2: Convert to fraction form
    949.50/1,422.78 = 640.20/x
  3. Step 3: Cross multiply
    949.50x = 1,422.78 × 640.20
  4. Step 4: Simplify right side
    949.50x = 910,863.76
  5. Step 5: Solve for x
    x = 910,863.76/949.50
  6. Step 6: Final answer
    x = 959.31

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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.