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Finding the Fourth Proportional to 390.14, 584.79 and 207.65

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Solution

The fourth proportional to 390.14, 584.79 and 207.65 is: 311.25

Step by Step Solution

  1. Step 1: Write the proportion equation
    390.14 : 584.79 = 207.65 : x
  2. Step 2: Convert to fraction form
    390.14/584.79 = 207.65/x
  3. Step 3: Cross multiply
    390.14x = 584.79 × 207.65
  4. Step 4: Simplify right side
    390.14x = 121,431.64
  5. Step 5: Solve for x
    x = 121,431.64/390.14
  6. Step 6: Final answer
    x = 311.25

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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.