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Finding the Fourth Proportional to 856.78, 1,284.90 and 271.77

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Solution

The fourth proportional to 856.78, 1,284.90 and 271.77 is: 407.57

Step by Step Solution

  1. Step 1: Write the proportion equation
    856.78 : 1,284.90 = 271.77 : x
  2. Step 2: Convert to fraction form
    856.78/1,284.90 = 271.77/x
  3. Step 3: Cross multiply
    856.78x = 1,284.90 × 271.77
  4. Step 4: Simplify right side
    856.78x = 349,197.27
  5. Step 5: Solve for x
    x = 349,197.27/856.78
  6. Step 6: Final answer
    x = 407.57

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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.