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Finding the Fourth Proportional to 640, 958.47 and 395.78

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Solution

The fourth proportional to 640, 958.47 and 395.78 is: 592.72

Step by Step Solution

  1. Step 1: Write the proportion equation
    640 : 958.47 = 395.78 : x
  2. Step 2: Convert to fraction form
    640/958.47 = 395.78/x
  3. Step 3: Cross multiply
    640x = 958.47 × 395.78
  4. Step 4: Simplify right side
    640x = 379,343.26
  5. Step 5: Solve for x
    x = 379,343.26/640
  6. Step 6: Final answer
    x = 592.72

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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.