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Finding the Fourth Proportional to 390.81, 586.06 and 130.76

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Solution

The fourth proportional to 390.81, 586.06 and 130.76 is: 196.08

Step by Step Solution

  1. Step 1: Write the proportion equation
    390.81 : 586.06 = 130.76 : x
  2. Step 2: Convert to fraction form
    390.81/586.06 = 130.76/x
  3. Step 3: Cross multiply
    390.81x = 586.06 × 130.76
  4. Step 4: Simplify right side
    390.81x = 76,630.87
  5. Step 5: Solve for x
    x = 76,630.87/390.81
  6. Step 6: Final answer
    x = 196.08

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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.