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Finding the Fourth Proportional to 538.20, 742.86 and 390.58

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Solution

The fourth proportional to 538.20, 742.86 and 390.58 is: 539.10

Step by Step Solution

  1. Step 1: Write the proportion equation
    538.20 : 742.86 = 390.58 : x
  2. Step 2: Convert to fraction form
    538.20/742.86 = 390.58/x
  3. Step 3: Cross multiply
    538.20x = 742.86 × 390.58
  4. Step 4: Simplify right side
    538.20x = 290,146.26
  5. Step 5: Solve for x
    x = 290,146.26/538.20
  6. Step 6: Final answer
    x = 539.10

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1.5x scale

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.