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Finding the Fourth Proportional to 640.38, 961.14 and 315.96

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Solution

The fourth proportional to 640.38, 961.14 and 315.96 is: 474.22

Step by Step Solution

  1. Step 1: Write the proportion equation
    640.38 : 961.14 = 315.96 : x
  2. Step 2: Convert to fraction form
    640.38/961.14 = 315.96/x
  3. Step 3: Cross multiply
    640.38x = 961.14 × 315.96
  4. Step 4: Simplify right side
    640.38x = 303,681.79
  5. Step 5: Solve for x
    x = 303,681.79/640.38
  6. Step 6: Final answer
    x = 474.22

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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.