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Finding the Fourth Proportional to 431.45, 647.20 and 123.28

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Solution

The fourth proportional to 431.45, 647.20 and 123.28 is: 184.93

Step by Step Solution

  1. Step 1: Write the proportion equation
    431.45 : 647.20 = 123.28 : x
  2. Step 2: Convert to fraction form
    431.45/647.20 = 123.28/x
  3. Step 3: Cross multiply
    431.45x = 647.20 × 123.28
  4. Step 4: Simplify right side
    431.45x = 79,786.57
  5. Step 5: Solve for x
    x = 79,786.57/431.45
  6. Step 6: Final answer
    x = 184.93

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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.