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Finding the Fourth Proportional to 1,285.44, 1,771.20 and 870.72

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Solution

The fourth proportional to 1,285.44, 1,771.20 and 870.72 is: 1,199.76

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,285.44 : 1,771.20 = 870.72 : x
  2. Step 2: Convert to fraction form
    1,285.44/1,771.20 = 870.72/x
  3. Step 3: Cross multiply
    1,285.44x = 1,771.20 × 870.72
  4. Step 4: Simplify right side
    1,285.44x = 1,542,219.26
  5. Step 5: Solve for x
    x = 1,542,219.26/1,285.44
  6. Step 6: Final answer
    x = 1,199.76

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1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.