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Finding the Fourth Proportional to 391.68, 539.40 and 275.04

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Solution

The fourth proportional to 391.68, 539.40 and 275.04 is: 378.77

Step by Step Solution

  1. Step 1: Write the proportion equation
    391.68 : 539.40 = 275.04 : x
  2. Step 2: Convert to fraction form
    391.68/539.40 = 275.04/x
  3. Step 3: Cross multiply
    391.68x = 539.40 × 275.04
  4. Step 4: Simplify right side
    391.68x = 148,356.58
  5. Step 5: Solve for x
    x = 148,356.58/391.68
  6. Step 6: Final answer
    x = 378.77

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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.