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Finding the Fourth Proportional to 856.49, 1,284.53 and 393.98

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Solution

The fourth proportional to 856.49, 1,284.53 and 393.98 is: 590.87

Step by Step Solution

  1. Step 1: Write the proportion equation
    856.49 : 1,284.53 = 393.98 : x
  2. Step 2: Convert to fraction form
    856.49/1,284.53 = 393.98/x
  3. Step 3: Cross multiply
    856.49x = 1,284.53 × 393.98
  4. Step 4: Simplify right side
    856.49x = 506,070.74
  5. Step 5: Solve for x
    x = 506,070.74/856.49
  6. Step 6: Final answer
    x = 590.87

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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.