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Finding the Fourth Proportional to 755.90, 1,041.28 and 645.74

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Solution

The fourth proportional to 755.90, 1,041.28 and 645.74 is: 889.53

Step by Step Solution

  1. Step 1: Write the proportion equation
    755.90 : 1,041.28 = 645.74 : x
  2. Step 2: Convert to fraction form
    755.90/1,041.28 = 645.74/x
  3. Step 3: Cross multiply
    755.90x = 1,041.28 × 645.74
  4. Step 4: Simplify right side
    755.90x = 672,396.15
  5. Step 5: Solve for x
    x = 672,396.15/755.90
  6. Step 6: Final answer
    x = 889.53

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.