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Finding the Fourth Proportional to 391.65, 587.65 and 208.83

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Solution

The fourth proportional to 391.65, 587.65 and 208.83 is: 313.34

Step by Step Solution

  1. Step 1: Write the proportion equation
    391.65 : 587.65 = 208.83 : x
  2. Step 2: Convert to fraction form
    391.65/587.65 = 208.83/x
  3. Step 3: Cross multiply
    391.65x = 587.65 × 208.83
  4. Step 4: Simplify right side
    391.65x = 122,718.95
  5. Step 5: Solve for x
    x = 122,718.95/391.65
  6. Step 6: Final answer
    x = 313.34

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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.