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Finding the Fourth Proportional to 391.68, 540.72 and 275.76

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Solution

The fourth proportional to 391.68, 540.72 and 275.76 is: 380.69

Step by Step Solution

  1. Step 1: Write the proportion equation
    391.68 : 540.72 = 275.76 : x
  2. Step 2: Convert to fraction form
    391.68/540.72 = 275.76/x
  3. Step 3: Cross multiply
    391.68x = 540.72 × 275.76
  4. Step 4: Simplify right side
    391.68x = 149,108.95
  5. Step 5: Solve for x
    x = 149,108.95/391.68
  6. Step 6: Final answer
    x = 380.69

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.