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Finding the Fourth Proportional to 538.14, 742.42 and 390.45

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Solution

The fourth proportional to 538.14, 742.42 and 390.45 is: 538.66

Step by Step Solution

  1. Step 1: Write the proportion equation
    538.14 : 742.42 = 390.45 : x
  2. Step 2: Convert to fraction form
    538.14/742.42 = 390.45/x
  3. Step 3: Cross multiply
    538.14x = 742.42 × 390.45
  4. Step 4: Simplify right side
    538.14x = 289,875.94
  5. Step 5: Solve for x
    x = 289,875.94/538.14
  6. Step 6: Final answer
    x = 538.66

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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.