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Finding the Fourth Proportional to 1,259.70, 1,889.01 and 642.75

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Solution

The fourth proportional to 1,259.70, 1,889.01 and 642.75 is: 963.85

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,259.70 : 1,889.01 = 642.75 : x
  2. Step 2: Convert to fraction form
    1,259.70/1,889.01 = 642.75/x
  3. Step 3: Cross multiply
    1,259.70x = 1,889.01 × 642.75
  4. Step 4: Simplify right side
    1,259.70x = 1,214,161.18
  5. Step 5: Solve for x
    x = 1,214,161.18/1,259.70
  6. Step 6: Final answer
    x = 963.85

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1.5x scale

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.