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Finding the Fourth Proportional to 640.25, 960.40 and 274.79

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Solution

The fourth proportional to 640.25, 960.40 and 274.79 is: 412.19

Step by Step Solution

  1. Step 1: Write the proportion equation
    640.25 : 960.40 = 274.79 : x
  2. Step 2: Convert to fraction form
    640.25/960.40 = 274.79/x
  3. Step 3: Cross multiply
    640.25x = 960.40 × 274.79
  4. Step 4: Simplify right side
    640.25x = 263,903.51
  5. Step 5: Solve for x
    x = 263,903.51/640.25
  6. Step 6: Final answer
    x = 412.19

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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.