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Finding the Fourth Proportional to 885.78, 1,321.07 and 871.20

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Solution

The fourth proportional to 885.78, 1,321.07 and 871.20 is: 1,299.32

Step by Step Solution

  1. Step 1: Write the proportion equation
    885.78 : 1,321.07 = 871.20 : x
  2. Step 2: Convert to fraction form
    885.78/1,321.07 = 871.20/x
  3. Step 3: Cross multiply
    885.78x = 1,321.07 × 871.20
  4. Step 4: Simplify right side
    885.78x = 1,150,911.83
  5. Step 5: Solve for x
    x = 1,150,911.83/885.78
  6. Step 6: Final answer
    x = 1,299.32

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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.