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Finding the Fourth Proportional to 390.29, 585.43 and 147.08

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Solution

The fourth proportional to 390.29, 585.43 and 147.08 is: 220.62

Step by Step Solution

  1. Step 1: Write the proportion equation
    390.29 : 585.43 = 147.08 : x
  2. Step 2: Convert to fraction form
    390.29/585.43 = 147.08/x
  3. Step 3: Cross multiply
    390.29x = 585.43 × 147.08
  4. Step 4: Simplify right side
    390.29x = 86,106.14
  5. Step 5: Solve for x
    x = 86,106.14/390.29
  6. Step 6: Final answer
    x = 220.62

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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.