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Finding the Fourth Proportional to 391.45, 586.69 and 247.21

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Solution

The fourth proportional to 391.45, 586.69 and 247.21 is: 370.50

Step by Step Solution

  1. Step 1: Write the proportion equation
    391.45 : 586.69 = 247.21 : x
  2. Step 2: Convert to fraction form
    391.45/586.69 = 247.21/x
  3. Step 3: Cross multiply
    391.45x = 586.69 × 247.21
  4. Step 4: Simplify right side
    391.45x = 145,031.47
  5. Step 5: Solve for x
    x = 145,031.47/391.45
  6. Step 6: Final answer
    x = 370.50

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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.