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Finding the Fourth Proportional to 872.20, 1,307.89 and 255.75

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Solution

The fourth proportional to 872.20, 1,307.89 and 255.75 is: 383.50

Step by Step Solution

  1. Step 1: Write the proportion equation
    872.20 : 1,307.89 = 255.75 : x
  2. Step 2: Convert to fraction form
    872.20/1,307.89 = 255.75/x
  3. Step 3: Cross multiply
    872.20x = 1,307.89 × 255.75
  4. Step 4: Simplify right side
    872.20x = 334,488.28
  5. Step 5: Solve for x
    x = 334,488.28/872.20
  6. Step 6: Final answer
    x = 383.50

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Double scale
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1.5x scale

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.