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Finding the Fourth Proportional to 646.96, 969.90 and 213.88

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Solution

The fourth proportional to 646.96, 969.90 and 213.88 is: 320.64

Step by Step Solution

  1. Step 1: Write the proportion equation
    646.96 : 969.90 = 213.88 : x
  2. Step 2: Convert to fraction form
    646.96/969.90 = 213.88/x
  3. Step 3: Cross multiply
    646.96x = 969.90 × 213.88
  4. Step 4: Simplify right side
    646.96x = 207,442.21
  5. Step 5: Solve for x
    x = 207,442.21/646.96
  6. Step 6: Final answer
    x = 320.64

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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.