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Finding the Fourth Proportional to 391.18, 586.78 and 185.64

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Solution

The fourth proportional to 391.18, 586.78 and 185.64 is: 278.47

Step by Step Solution

  1. Step 1: Write the proportion equation
    391.18 : 586.78 = 185.64 : x
  2. Step 2: Convert to fraction form
    391.18/586.78 = 185.64/x
  3. Step 3: Cross multiply
    391.18x = 586.78 × 185.64
  4. Step 4: Simplify right side
    391.18x = 108,929.84
  5. Step 5: Solve for x
    x = 108,929.84/391.18
  6. Step 6: Final answer
    x = 278.47

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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.