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Finding the Fourth Proportional to 640.40, 960.74 and 201.72

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Solution

The fourth proportional to 640.40, 960.74 and 201.72 is: 302.63

Step by Step Solution

  1. Step 1: Write the proportion equation
    640.40 : 960.74 = 201.72 : x
  2. Step 2: Convert to fraction form
    640.40/960.74 = 201.72/x
  3. Step 3: Cross multiply
    640.40x = 960.74 × 201.72
  4. Step 4: Simplify right side
    640.40x = 193,802.59
  5. Step 5: Solve for x
    x = 193,802.59/640.40
  6. Step 6: Final answer
    x = 302.63

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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.