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Finding the Fourth Proportional to 905.72, 1,249.90 and 512.75

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Solution

The fourth proportional to 905.72, 1,249.90 and 512.75 is: 707.60

Step by Step Solution

  1. Step 1: Write the proportion equation
    905.72 : 1,249.90 = 512.75 : x
  2. Step 2: Convert to fraction form
    905.72/1,249.90 = 512.75/x
  3. Step 3: Cross multiply
    905.72x = 1,249.90 × 512.75
  4. Step 4: Simplify right side
    905.72x = 640,886.23
  5. Step 5: Solve for x
    x = 640,886.23/905.72
  6. Step 6: Final answer
    x = 707.60

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Double scale
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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.