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Finding the Fourth Proportional to 900.57, 1,242.89 and 620.71

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Solution

The fourth proportional to 900.57, 1,242.89 and 620.71 is: 856.65

Step by Step Solution

  1. Step 1: Write the proportion equation
    900.57 : 1,242.89 = 620.71 : x
  2. Step 2: Convert to fraction form
    900.57/1,242.89 = 620.71/x
  3. Step 3: Cross multiply
    900.57x = 1,242.89 × 620.71
  4. Step 4: Simplify right side
    900.57x = 771,471.15
  5. Step 5: Solve for x
    x = 771,471.15/900.57
  6. Step 6: Final answer
    x = 856.65

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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.