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Finding the Fourth Proportional to 390.76, 586.34 and 198.38

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Solution

The fourth proportional to 390.76, 586.34 and 198.38 is: 297.67

Step by Step Solution

  1. Step 1: Write the proportion equation
    390.76 : 586.34 = 198.38 : x
  2. Step 2: Convert to fraction form
    390.76/586.34 = 198.38/x
  3. Step 3: Cross multiply
    390.76x = 586.34 × 198.38
  4. Step 4: Simplify right side
    390.76x = 116,318.13
  5. Step 5: Solve for x
    x = 116,318.13/390.76
  6. Step 6: Final answer
    x = 297.67

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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.