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Finding the Fourth Proportional to 208.87, 313.30 and 128.27

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Solution

The fourth proportional to 208.87, 313.30 and 128.27 is: 192.40

Step by Step Solution

  1. Step 1: Write the proportion equation
    208.87 : 313.30 = 128.27 : x
  2. Step 2: Convert to fraction form
    208.87/313.30 = 128.27/x
  3. Step 3: Cross multiply
    208.87x = 313.30 × 128.27
  4. Step 4: Simplify right side
    208.87x = 40,186.99
  5. Step 5: Solve for x
    x = 40,186.99/208.87
  6. Step 6: Final answer
    x = 192.40

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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.