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Finding the Fourth Proportional to 640.40, 958.86 and 380.18

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Solution

The fourth proportional to 640.40, 958.86 and 380.18 is: 569.23

Step by Step Solution

  1. Step 1: Write the proportion equation
    640.40 : 958.86 = 380.18 : x
  2. Step 2: Convert to fraction form
    640.40/958.86 = 380.18/x
  3. Step 3: Cross multiply
    640.40x = 958.86 × 380.18
  4. Step 4: Simplify right side
    640.40x = 364,534.60
  5. Step 5: Solve for x
    x = 364,534.60/640.40
  6. Step 6: Final answer
    x = 569.23

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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.