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Finding the Fourth Proportional to 862.79, 1,285.85 and 861.41

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Solution

The fourth proportional to 862.79, 1,285.85 and 861.41 is: 1,283.81

Step by Step Solution

  1. Step 1: Write the proportion equation
    862.79 : 1,285.85 = 861.41 : x
  2. Step 2: Convert to fraction form
    862.79/1,285.85 = 861.41/x
  3. Step 3: Cross multiply
    862.79x = 1,285.85 × 861.41
  4. Step 4: Simplify right side
    862.79x = 1,107,649.42
  5. Step 5: Solve for x
    x = 1,107,649.42/862.79
  6. Step 6: Final answer
    x = 1,283.81

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1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.