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Finding the Fourth Proportional to 856.90, 1,284.18 and 394.48

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Solution

The fourth proportional to 856.90, 1,284.18 and 394.48 is: 591.18

Step by Step Solution

  1. Step 1: Write the proportion equation
    856.90 : 1,284.18 = 394.48 : x
  2. Step 2: Convert to fraction form
    856.90/1,284.18 = 394.48/x
  3. Step 3: Cross multiply
    856.90x = 1,284.18 × 394.48
  4. Step 4: Simplify right side
    856.90x = 506,583.33
  5. Step 5: Solve for x
    x = 506,583.33/856.90
  6. Step 6: Final answer
    x = 591.18

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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.