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Finding the Fourth Proportional to 856.64, 1,284.96 and 445.90

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Solution

The fourth proportional to 856.64, 1,284.96 and 445.90 is: 668.84

Step by Step Solution

  1. Step 1: Write the proportion equation
    856.64 : 1,284.96 = 445.90 : x
  2. Step 2: Convert to fraction form
    856.64/1,284.96 = 445.90/x
  3. Step 3: Cross multiply
    856.64x = 1,284.96 × 445.90
  4. Step 4: Simplify right side
    856.64x = 572,960.45
  5. Step 5: Solve for x
    x = 572,960.45/856.64
  6. Step 6: Final answer
    x = 668.84

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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.