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Finding the Fourth Proportional to 390.80, 586.20 and 234.20

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Solution

The fourth proportional to 390.80, 586.20 and 234.20 is: 351.30

Step by Step Solution

  1. Step 1: Write the proportion equation
    390.80 : 586.20 = 234.20 : x
  2. Step 2: Convert to fraction form
    390.80/586.20 = 234.20/x
  3. Step 3: Cross multiply
    390.80x = 586.20 × 234.20
  4. Step 4: Simplify right side
    390.80x = 137,288.04
  5. Step 5: Solve for x
    x = 137,288.04/390.80
  6. Step 6: Final answer
    x = 351.30

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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.