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Finding the Fourth Proportional to 640.39, 883.65 and 419.65

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Solution

The fourth proportional to 640.39, 883.65 and 419.65 is: 579.06

Step by Step Solution

  1. Step 1: Write the proportion equation
    640.39 : 883.65 = 419.65 : x
  2. Step 2: Convert to fraction form
    640.39/883.65 = 419.65/x
  3. Step 3: Cross multiply
    640.39x = 883.65 × 419.65
  4. Step 4: Simplify right side
    640.39x = 370,823.72
  5. Step 5: Solve for x
    x = 370,823.72/640.39
  6. Step 6: Final answer
    x = 579.06

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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.