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Finding the Fourth Proportional to 407.80, 611.96 and 215.56

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Solution

The fourth proportional to 407.80, 611.96 and 215.56 is: 323.48

Step by Step Solution

  1. Step 1: Write the proportion equation
    407.80 : 611.96 = 215.56 : x
  2. Step 2: Convert to fraction form
    407.80/611.96 = 215.56/x
  3. Step 3: Cross multiply
    407.80x = 611.96 × 215.56
  4. Step 4: Simplify right side
    407.80x = 131,914.10
  5. Step 5: Solve for x
    x = 131,914.10/407.80
  6. Step 6: Final answer
    x = 323.48

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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.