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Finding the Fourth Proportional to 640.31, 960.46 and 421.00

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Solution

The fourth proportional to 640.31, 960.46 and 421.00 is: 631.50

Step by Step Solution

  1. Step 1: Write the proportion equation
    640.31 : 960.46 = 421.00 : x
  2. Step 2: Convert to fraction form
    640.31/960.46 = 421.00/x
  3. Step 3: Cross multiply
    640.31x = 960.46 × 421.00
  4. Step 4: Simplify right side
    640.31x = 404,350.21
  5. Step 5: Solve for x
    x = 404,350.21/640.31
  6. Step 6: Final answer
    x = 631.50

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Similar ratio
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1.5x scale

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.