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Finding the Fourth Proportional to 905.45, 1,249.52 and 491.45

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Solution

The fourth proportional to 905.45, 1,249.52 and 491.45 is: 678.19

Step by Step Solution

  1. Step 1: Write the proportion equation
    905.45 : 1,249.52 = 491.45 : x
  2. Step 2: Convert to fraction form
    905.45/1,249.52 = 491.45/x
  3. Step 3: Cross multiply
    905.45x = 1,249.52 × 491.45
  4. Step 4: Simplify right side
    905.45x = 614,067.90
  5. Step 5: Solve for x
    x = 614,067.90/905.45
  6. Step 6: Final answer
    x = 678.19

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1.5x scale

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.