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Finding the Fourth Proportional to 856.21, 1,283.48 and 445.39

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Solution

The fourth proportional to 856.21, 1,283.48 and 445.39 is: 667.65

Step by Step Solution

  1. Step 1: Write the proportion equation
    856.21 : 1,283.48 = 445.39 : x
  2. Step 2: Convert to fraction form
    856.21/1,283.48 = 445.39/x
  3. Step 3: Cross multiply
    856.21x = 1,283.48 × 445.39
  4. Step 4: Simplify right side
    856.21x = 571,649.16
  5. Step 5: Solve for x
    x = 571,649.16/856.21
  6. Step 6: Final answer
    x = 667.65

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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.