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Finding the Fourth Proportional to 679.95, 938.46 and 385.21

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Solution

The fourth proportional to 679.95, 938.46 and 385.21 is: 531.67

Step by Step Solution

  1. Step 1: Write the proportion equation
    679.95 : 938.46 = 385.21 : x
  2. Step 2: Convert to fraction form
    679.95/938.46 = 385.21/x
  3. Step 3: Cross multiply
    679.95x = 938.46 × 385.21
  4. Step 4: Simplify right side
    679.95x = 361,506.03
  5. Step 5: Solve for x
    x = 361,506.03/679.95
  6. Step 6: Final answer
    x = 531.67

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.