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Finding the Fourth Proportional to 390.86, 586.29 and 345.65

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Solution

The fourth proportional to 390.86, 586.29 and 345.65 is: 518.48

Step by Step Solution

  1. Step 1: Write the proportion equation
    390.86 : 586.29 = 345.65 : x
  2. Step 2: Convert to fraction form
    390.86/586.29 = 345.65/x
  3. Step 3: Cross multiply
    390.86x = 586.29 × 345.65
  4. Step 4: Simplify right side
    390.86x = 202,651.14
  5. Step 5: Solve for x
    x = 202,651.14/390.86
  6. Step 6: Final answer
    x = 518.48

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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.