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Finding the Fourth Proportional to 639.93, 959.86 and 315.19

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Solution

The fourth proportional to 639.93, 959.86 and 315.19 is: 472.76

Step by Step Solution

  1. Step 1: Write the proportion equation
    639.93 : 959.86 = 315.19 : x
  2. Step 2: Convert to fraction form
    639.93/959.86 = 315.19/x
  3. Step 3: Cross multiply
    639.93x = 959.86 × 315.19
  4. Step 4: Simplify right side
    639.93x = 302,536.27
  5. Step 5: Solve for x
    x = 302,536.27/639.93
  6. Step 6: Final answer
    x = 472.76

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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.