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Finding the Fourth Proportional to 1,285, 1,927.50 and 419.38

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Solution

The fourth proportional to 1,285, 1,927.50 and 419.38 is: 629.07

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,285 : 1,927.50 = 419.38 : x
  2. Step 2: Convert to fraction form
    1,285/1,927.50 = 419.38/x
  3. Step 3: Cross multiply
    1,285x = 1,927.50 × 419.38
  4. Step 4: Simplify right side
    1,285x = 808,354.95
  5. Step 5: Solve for x
    x = 808,354.95/1,285
  6. Step 6: Final answer
    x = 629.07

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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.