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Finding the Fourth Proportional to 315.40, 435.20 and 217.12

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Solution

The fourth proportional to 315.40, 435.20 and 217.12 is: 299.59

Step by Step Solution

  1. Step 1: Write the proportion equation
    315.40 : 435.20 = 217.12 : x
  2. Step 2: Convert to fraction form
    315.40/435.20 = 217.12/x
  3. Step 3: Cross multiply
    315.40x = 435.20 × 217.12
  4. Step 4: Simplify right side
    315.40x = 94,490.62
  5. Step 5: Solve for x
    x = 94,490.62/315.40
  6. Step 6: Final answer
    x = 299.59

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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.