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Finding the Fourth Proportional to 390.54, 585.95 and 208.07

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Solution

The fourth proportional to 390.54, 585.95 and 208.07 is: 312.18

Step by Step Solution

  1. Step 1: Write the proportion equation
    390.54 : 585.95 = 208.07 : x
  2. Step 2: Convert to fraction form
    390.54/585.95 = 208.07/x
  3. Step 3: Cross multiply
    390.54x = 585.95 × 208.07
  4. Step 4: Simplify right side
    390.54x = 121,918.62
  5. Step 5: Solve for x
    x = 121,918.62/390.54
  6. Step 6: Final answer
    x = 312.18

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.