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Finding the Fourth Proportional to 856.49, 1,283.72 and 393.89

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Solution

The fourth proportional to 856.49, 1,283.72 and 393.89 is: 590.36

Step by Step Solution

  1. Step 1: Write the proportion equation
    856.49 : 1,283.72 = 393.89 : x
  2. Step 2: Convert to fraction form
    856.49/1,283.72 = 393.89/x
  3. Step 3: Cross multiply
    856.49x = 1,283.72 × 393.89
  4. Step 4: Simplify right side
    856.49x = 505,638.05
  5. Step 5: Solve for x
    x = 505,638.05/856.49
  6. Step 6: Final answer
    x = 590.36

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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.