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Finding the Fourth Proportional to 856.36, 1,281.88 and 660.86

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Solution

The fourth proportional to 856.36, 1,281.88 and 660.86 is: 989.24

Step by Step Solution

  1. Step 1: Write the proportion equation
    856.36 : 1,281.88 = 660.86 : x
  2. Step 2: Convert to fraction form
    856.36/1,281.88 = 660.86/x
  3. Step 3: Cross multiply
    856.36x = 1,281.88 × 660.86
  4. Step 4: Simplify right side
    856.36x = 847,143.22
  5. Step 5: Solve for x
    x = 847,143.22/856.36
  6. Step 6: Final answer
    x = 989.24

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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.