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Finding the Fourth Proportional to 640.60, 883.58 and 378.40

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Solution

The fourth proportional to 640.60, 883.58 and 378.40 is: 521.93

Step by Step Solution

  1. Step 1: Write the proportion equation
    640.60 : 883.58 = 378.40 : x
  2. Step 2: Convert to fraction form
    640.60/883.58 = 378.40/x
  3. Step 3: Cross multiply
    640.60x = 883.58 × 378.40
  4. Step 4: Simplify right side
    640.60x = 334,346.67
  5. Step 5: Solve for x
    x = 334,346.67/640.60
  6. Step 6: Final answer
    x = 521.93

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.