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Finding the Fourth Proportional to 856.64, 1,284.48 and 279.36

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Solution

The fourth proportional to 856.64, 1,284.48 and 279.36 is: 418.88

Step by Step Solution

  1. Step 1: Write the proportion equation
    856.64 : 1,284.48 = 279.36 : x
  2. Step 2: Convert to fraction form
    856.64/1,284.48 = 279.36/x
  3. Step 3: Cross multiply
    856.64x = 1,284.48 × 279.36
  4. Step 4: Simplify right side
    856.64x = 358,832.33
  5. Step 5: Solve for x
    x = 358,832.33/856.64
  6. Step 6: Final answer
    x = 418.88

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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.