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Finding the Fourth Proportional to 856.64, 1,284.24 and 394.64

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Solution

The fourth proportional to 856.64, 1,284.24 and 394.64 is: 591.63

Step by Step Solution

  1. Step 1: Write the proportion equation
    856.64 : 1,284.24 = 394.64 : x
  2. Step 2: Convert to fraction form
    856.64/1,284.24 = 394.64/x
  3. Step 3: Cross multiply
    856.64x = 1,284.24 × 394.64
  4. Step 4: Simplify right side
    856.64x = 506,812.47
  5. Step 5: Solve for x
    x = 506,812.47/856.64
  6. Step 6: Final answer
    x = 591.63

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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.