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Finding the Fourth Proportional to 640.49, 960.26 and 421.18

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Solution

The fourth proportional to 640.49, 960.26 and 421.18 is: 631.46

Step by Step Solution

  1. Step 1: Write the proportion equation
    640.49 : 960.26 = 421.18 : x
  2. Step 2: Convert to fraction form
    640.49/960.26 = 421.18/x
  3. Step 3: Cross multiply
    640.49x = 960.26 × 421.18
  4. Step 4: Simplify right side
    640.49x = 404,437.80
  5. Step 5: Solve for x
    x = 404,437.80/640.49
  6. Step 6: Final answer
    x = 631.46

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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.