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Finding the Fourth Proportional to 858.61, 1,288.31 and 419.62

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Solution

The fourth proportional to 858.61, 1,288.31 and 419.62 is: 629.62

Step by Step Solution

  1. Step 1: Write the proportion equation
    858.61 : 1,288.31 = 419.62 : x
  2. Step 2: Convert to fraction form
    858.61/1,288.31 = 419.62/x
  3. Step 3: Cross multiply
    858.61x = 1,288.31 × 419.62
  4. Step 4: Simplify right side
    858.61x = 540,600.64
  5. Step 5: Solve for x
    x = 540,600.64/858.61
  6. Step 6: Final answer
    x = 629.62

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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.