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Finding the Fourth Proportional to 759.89, 1,140.48 and 643.49

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Solution

The fourth proportional to 759.89, 1,140.48 and 643.49 is: 965.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    759.89 : 1,140.48 = 643.49 : x
  2. Step 2: Convert to fraction form
    759.89/1,140.48 = 643.49/x
  3. Step 3: Cross multiply
    759.89x = 1,140.48 × 643.49
  4. Step 4: Simplify right side
    759.89x = 733,887.48
  5. Step 5: Solve for x
    x = 733,887.48/759.89
  6. Step 6: Final answer
    x = 965.78

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Double scale
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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.