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Finding the Fourth Proportional to 1,275, 1,912.50 and 505.50

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Solution

The fourth proportional to 1,275, 1,912.50 and 505.50 is: 758.25

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,275 : 1,912.50 = 505.50 : x
  2. Step 2: Convert to fraction form
    1,275/1,912.50 = 505.50/x
  3. Step 3: Cross multiply
    1,275x = 1,912.50 × 505.50
  4. Step 4: Simplify right side
    1,275x = 966,768.75
  5. Step 5: Solve for x
    x = 966,768.75/1,275
  6. Step 6: Final answer
    x = 758.25

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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.