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Finding the Fourth Proportional to 390.88, 586.64 and 208.41

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Solution

The fourth proportional to 390.88, 586.64 and 208.41 is: 312.79

Step by Step Solution

  1. Step 1: Write the proportion equation
    390.88 : 586.64 = 208.41 : x
  2. Step 2: Convert to fraction form
    390.88/586.64 = 208.41/x
  3. Step 3: Cross multiply
    390.88x = 586.64 × 208.41
  4. Step 4: Simplify right side
    390.88x = 122,261.64
  5. Step 5: Solve for x
    x = 122,261.64/390.88
  6. Step 6: Final answer
    x = 312.79

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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.