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Finding the Fourth Proportional to 390.72, 586.14 and 130.74

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Solution

The fourth proportional to 390.72, 586.14 and 130.74 is: 196.13

Step by Step Solution

  1. Step 1: Write the proportion equation
    390.72 : 586.14 = 130.74 : x
  2. Step 2: Convert to fraction form
    390.72/586.14 = 130.74/x
  3. Step 3: Cross multiply
    390.72x = 586.14 × 130.74
  4. Step 4: Simplify right side
    390.72x = 76,631.94
  5. Step 5: Solve for x
    x = 76,631.94/390.72
  6. Step 6: Final answer
    x = 196.13

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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.