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Finding the Fourth Proportional to 391.40, 586.86 and 185.69

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Solution

The fourth proportional to 391.40, 586.86 and 185.69 is: 278.42

Step by Step Solution

  1. Step 1: Write the proportion equation
    391.40 : 586.86 = 185.69 : x
  2. Step 2: Convert to fraction form
    391.40/586.86 = 185.69/x
  3. Step 3: Cross multiply
    391.40x = 586.86 × 185.69
  4. Step 4: Simplify right side
    391.40x = 108,974.03
  5. Step 5: Solve for x
    x = 108,974.03/391.40
  6. Step 6: Final answer
    x = 278.42

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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.