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Finding the Fourth Proportional to 391.76, 586.62 and 380.21

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Solution

The fourth proportional to 391.76, 586.62 and 380.21 is: 569.33

Step by Step Solution

  1. Step 1: Write the proportion equation
    391.76 : 586.62 = 380.21 : x
  2. Step 2: Convert to fraction form
    391.76/586.62 = 380.21/x
  3. Step 3: Cross multiply
    391.76x = 586.62 × 380.21
  4. Step 4: Simplify right side
    391.76x = 223,036.89
  5. Step 5: Solve for x
    x = 223,036.89/391.76
  6. Step 6: Final answer
    x = 569.33

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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.