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Finding the Fourth Proportional to 614.40, 921.60 and 419.55

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Solution

The fourth proportional to 614.40, 921.60 and 419.55 is: 629.33

Step by Step Solution

  1. Step 1: Write the proportion equation
    614.40 : 921.60 = 419.55 : x
  2. Step 2: Convert to fraction form
    614.40/921.60 = 419.55/x
  3. Step 3: Cross multiply
    614.40x = 921.60 × 419.55
  4. Step 4: Simplify right side
    614.40x = 386,657.28
  5. Step 5: Solve for x
    x = 386,657.28/614.40
  6. Step 6: Final answer
    x = 629.33

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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.