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Finding the Fourth Proportional to 538.40, 742.58 and 391.16

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Solution

The fourth proportional to 538.40, 742.58 and 391.16 is: 539.50

Step by Step Solution

  1. Step 1: Write the proportion equation
    538.40 : 742.58 = 391.16 : x
  2. Step 2: Convert to fraction form
    538.40/742.58 = 391.16/x
  3. Step 3: Cross multiply
    538.40x = 742.58 × 391.16
  4. Step 4: Simplify right side
    538.40x = 290,467.59
  5. Step 5: Solve for x
    x = 290,467.59/538.40
  6. Step 6: Final answer
    x = 539.50

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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.