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Finding the Fourth Proportional to 678.98, 1,015.50 and 629.75

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Solution

The fourth proportional to 678.98, 1,015.50 and 629.75 is: 941.87

Step by Step Solution

  1. Step 1: Write the proportion equation
    678.98 : 1,015.50 = 629.75 : x
  2. Step 2: Convert to fraction form
    678.98/1,015.50 = 629.75/x
  3. Step 3: Cross multiply
    678.98x = 1,015.50 × 629.75
  4. Step 4: Simplify right side
    678.98x = 639,516.03
  5. Step 5: Solve for x
    x = 639,516.03/678.98
  6. Step 6: Final answer
    x = 941.87

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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.