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Finding the Fourth Proportional to 391.65, 586.94 and 208.80

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Solution

The fourth proportional to 391.65, 586.94 and 208.80 is: 312.91

Step by Step Solution

  1. Step 1: Write the proportion equation
    391.65 : 586.94 = 208.80 : x
  2. Step 2: Convert to fraction form
    391.65/586.94 = 208.80/x
  3. Step 3: Cross multiply
    391.65x = 586.94 × 208.80
  4. Step 4: Simplify right side
    391.65x = 122,552.03
  5. Step 5: Solve for x
    x = 122,552.03/391.65
  6. Step 6: Final answer
    x = 312.91

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These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.