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Finding the Fourth Proportional to 390.29, 584.91 and 317.39

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Solution

The fourth proportional to 390.29, 584.91 and 317.39 is: 475.66

Step by Step Solution

  1. Step 1: Write the proportion equation
    390.29 : 584.91 = 317.39 : x
  2. Step 2: Convert to fraction form
    390.29/584.91 = 317.39/x
  3. Step 3: Cross multiply
    390.29x = 584.91 × 317.39
  4. Step 4: Simplify right side
    390.29x = 185,641.66
  5. Step 5: Solve for x
    x = 185,641.66/390.29
  6. Step 6: Final answer
    x = 475.66

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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.