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Finding the Fourth Proportional to 639.79, 958.77 and 315.38

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Solution

The fourth proportional to 639.79, 958.77 and 315.38 is: 472.62

Step by Step Solution

  1. Step 1: Write the proportion equation
    639.79 : 958.77 = 315.38 : x
  2. Step 2: Convert to fraction form
    639.79/958.77 = 315.38/x
  3. Step 3: Cross multiply
    639.79x = 958.77 × 315.38
  4. Step 4: Simplify right side
    639.79x = 302,379.28
  5. Step 5: Solve for x
    x = 302,379.28/639.79
  6. Step 6: Final answer
    x = 472.62

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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.