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Finding the Fourth Proportional to 390.09, 582.09 and 355.59

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Solution

The fourth proportional to 390.09, 582.09 and 355.59 is: 530.61

Step by Step Solution

  1. Step 1: Write the proportion equation
    390.09 : 582.09 = 355.59 : x
  2. Step 2: Convert to fraction form
    390.09/582.09 = 355.59/x
  3. Step 3: Cross multiply
    390.09x = 582.09 × 355.59
  4. Step 4: Simplify right side
    390.09x = 206,985.38
  5. Step 5: Solve for x
    x = 206,985.38/390.09
  6. Step 6: Final answer
    x = 530.61

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.