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Finding the Fourth Proportional to 639.99, 960.39 and 315.18

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Solution

The fourth proportional to 639.99, 960.39 and 315.18 is: 472.97

Step by Step Solution

  1. Step 1: Write the proportion equation
    639.99 : 960.39 = 315.18 : x
  2. Step 2: Convert to fraction form
    639.99/960.39 = 315.18/x
  3. Step 3: Cross multiply
    639.99x = 960.39 × 315.18
  4. Step 4: Simplify right side
    639.99x = 302,695.72
  5. Step 5: Solve for x
    x = 302,695.72/639.99
  6. Step 6: Final answer
    x = 472.97

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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.