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Finding the Fourth Proportional to 1,391.75, 2,087.62 and 641.17

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Solution

The fourth proportional to 1,391.75, 2,087.62 and 641.17 is: 961.75

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,391.75 : 2,087.62 = 641.17 : x
  2. Step 2: Convert to fraction form
    1,391.75/2,087.62 = 641.17/x
  3. Step 3: Cross multiply
    1,391.75x = 2,087.62 × 641.17
  4. Step 4: Simplify right side
    1,391.75x = 1,338,519.32
  5. Step 5: Solve for x
    x = 1,338,519.32/1,391.75
  6. Step 6: Final answer
    x = 961.75

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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.