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Finding the Fourth Proportional to 323.99, 485.65 and 128.91

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Solution

The fourth proportional to 323.99, 485.65 and 128.91 is: 193.23

Step by Step Solution

  1. Step 1: Write the proportion equation
    323.99 : 485.65 = 128.91 : x
  2. Step 2: Convert to fraction form
    323.99/485.65 = 128.91/x
  3. Step 3: Cross multiply
    323.99x = 485.65 × 128.91
  4. Step 4: Simplify right side
    323.99x = 62,606.40
  5. Step 5: Solve for x
    x = 62,606.40/323.99
  6. Step 6: Final answer
    x = 193.23

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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.