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Finding the Fourth Proportional to 1,280.21, 1,764.56 and 906.71

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Solution

The fourth proportional to 1,280.21, 1,764.56 and 906.71 is: 1,249.75

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,280.21 : 1,764.56 = 906.71 : x
  2. Step 2: Convert to fraction form
    1,280.21/1,764.56 = 906.71/x
  3. Step 3: Cross multiply
    1,280.21x = 1,764.56 × 906.71
  4. Step 4: Simplify right side
    1,280.21x = 1,599,930.84
  5. Step 5: Solve for x
    x = 1,599,930.84/1,280.21
  6. Step 6: Final answer
    x = 1,249.75

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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.