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Finding the Fourth Proportional to 638.99, 960.08 and 407.98

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Solution

The fourth proportional to 638.99, 960.08 and 407.98 is: 612.99

Step by Step Solution

  1. Step 1: Write the proportion equation
    638.99 : 960.08 = 407.98 : x
  2. Step 2: Convert to fraction form
    638.99/960.08 = 407.98/x
  3. Step 3: Cross multiply
    638.99x = 960.08 × 407.98
  4. Step 4: Simplify right side
    638.99x = 391,689.00
  5. Step 5: Solve for x
    x = 391,689.00/638.99
  6. Step 6: Final answer
    x = 612.99

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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.