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Finding the Fourth Proportional to 390.15, 585.23 and 217.08

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Solution

The fourth proportional to 390.15, 585.23 and 217.08 is: 325.62

Step by Step Solution

  1. Step 1: Write the proportion equation
    390.15 : 585.23 = 217.08 : x
  2. Step 2: Convert to fraction form
    390.15/585.23 = 217.08/x
  3. Step 3: Cross multiply
    390.15x = 585.23 × 217.08
  4. Step 4: Simplify right side
    390.15x = 127,040.64
  5. Step 5: Solve for x
    x = 127,040.64/390.15
  6. Step 6: Final answer
    x = 325.62

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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.