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Finding the Fourth Proportional to 390.15, 585.34 and 130.18

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Solution

The fourth proportional to 390.15, 585.34 and 130.18 is: 195.30

Step by Step Solution

  1. Step 1: Write the proportion equation
    390.15 : 585.34 = 130.18 : x
  2. Step 2: Convert to fraction form
    390.15/585.34 = 130.18/x
  3. Step 3: Cross multiply
    390.15x = 585.34 × 130.18
  4. Step 4: Simplify right side
    390.15x = 76,195.98
  5. Step 5: Solve for x
    x = 76,195.98/390.15
  6. Step 6: Final answer
    x = 195.30

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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.