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Finding the Fourth Proportional to 876.28, 1,209.78 and 679.36

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Solution

The fourth proportional to 876.28, 1,209.78 and 679.36 is: 937.91

Step by Step Solution

  1. Step 1: Write the proportion equation
    876.28 : 1,209.78 = 679.36 : x
  2. Step 2: Convert to fraction form
    876.28/1,209.78 = 679.36/x
  3. Step 3: Cross multiply
    876.28x = 1,209.78 × 679.36
  4. Step 4: Simplify right side
    876.28x = 821,876.14
  5. Step 5: Solve for x
    x = 821,876.14/876.28
  6. Step 6: Final answer
    x = 937.91

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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.