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Finding the Fourth Proportional to 856.86, 1,284.21 and 613.86

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Solution

The fourth proportional to 856.86, 1,284.21 and 613.86 is: 920.02

Step by Step Solution

  1. Step 1: Write the proportion equation
    856.86 : 1,284.21 = 613.86 : x
  2. Step 2: Convert to fraction form
    856.86/1,284.21 = 613.86/x
  3. Step 3: Cross multiply
    856.86x = 1,284.21 × 613.86
  4. Step 4: Simplify right side
    856.86x = 788,325.15
  5. Step 5: Solve for x
    x = 788,325.15/856.86
  6. Step 6: Final answer
    x = 920.02

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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.