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Finding the Fourth Proportional to 391.23, 538.47 and 280.53

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Solution

The fourth proportional to 391.23, 538.47 and 280.53 is: 386.11

Step by Step Solution

  1. Step 1: Write the proportion equation
    391.23 : 538.47 = 280.53 : x
  2. Step 2: Convert to fraction form
    391.23/538.47 = 280.53/x
  3. Step 3: Cross multiply
    391.23x = 538.47 × 280.53
  4. Step 4: Simplify right side
    391.23x = 151,056.99
  5. Step 5: Solve for x
    x = 151,056.99/391.23
  6. Step 6: Final answer
    x = 386.11

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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.