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Finding the Fourth Proportional to 419.63, 629.85 and 257.63

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Solution

The fourth proportional to 419.63, 629.85 and 257.63 is: 386.69

Step by Step Solution

  1. Step 1: Write the proportion equation
    419.63 : 629.85 = 257.63 : x
  2. Step 2: Convert to fraction form
    419.63/629.85 = 257.63/x
  3. Step 3: Cross multiply
    419.63x = 629.85 × 257.63
  4. Step 4: Simplify right side
    419.63x = 162,268.26
  5. Step 5: Solve for x
    x = 162,268.26/419.63
  6. Step 6: Final answer
    x = 386.69

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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.