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Finding the Fourth Proportional to 1,420.71, 2,131.06 and 641.08

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Solution

The fourth proportional to 1,420.71, 2,131.06 and 641.08 is: 961.61

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,420.71 : 2,131.06 = 641.08 : x
  2. Step 2: Convert to fraction form
    1,420.71/2,131.06 = 641.08/x
  3. Step 3: Cross multiply
    1,420.71x = 2,131.06 × 641.08
  4. Step 4: Simplify right side
    1,420.71x = 1,366,170.22
  5. Step 5: Solve for x
    x = 1,366,170.22/1,420.71
  6. Step 6: Final answer
    x = 961.61

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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.