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Finding the Fourth Proportional to 879.40, 1,213.54 and 627.78

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Solution

The fourth proportional to 879.40, 1,213.54 and 627.78 is: 866.31

Step by Step Solution

  1. Step 1: Write the proportion equation
    879.40 : 1,213.54 = 627.78 : x
  2. Step 2: Convert to fraction form
    879.40/1,213.54 = 627.78/x
  3. Step 3: Cross multiply
    879.40x = 1,213.54 × 627.78
  4. Step 4: Simplify right side
    879.40x = 761,836.14
  5. Step 5: Solve for x
    x = 761,836.14/879.40
  6. Step 6: Final answer
    x = 866.31

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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.