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Finding the Fourth Proportional to 390.12, 538.56 and 259.20

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Solution

The fourth proportional to 390.12, 538.56 and 259.20 is: 357.83

Step by Step Solution

  1. Step 1: Write the proportion equation
    390.12 : 538.56 = 259.20 : x
  2. Step 2: Convert to fraction form
    390.12/538.56 = 259.20/x
  3. Step 3: Cross multiply
    390.12x = 538.56 × 259.20
  4. Step 4: Simplify right side
    390.12x = 139,594.75
  5. Step 5: Solve for x
    x = 139,594.75/390.12
  6. Step 6: Final answer
    x = 357.83

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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.