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Finding the Fourth Proportional to 412.79, 618.88 and 207.21

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Solution

The fourth proportional to 412.79, 618.88 and 207.21 is: 310.66

Step by Step Solution

  1. Step 1: Write the proportion equation
    412.79 : 618.88 = 207.21 : x
  2. Step 2: Convert to fraction form
    412.79/618.88 = 207.21/x
  3. Step 3: Cross multiply
    412.79x = 618.88 × 207.21
  4. Step 4: Simplify right side
    412.79x = 128,238.12
  5. Step 5: Solve for x
    x = 128,238.12/412.79
  6. Step 6: Final answer
    x = 310.66

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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.