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Finding the Fourth Proportional to 869.86, 1,200.80 and 555.55

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Solution

The fourth proportional to 869.86, 1,200.80 and 555.55 is: 766.91

Step by Step Solution

  1. Step 1: Write the proportion equation
    869.86 : 1,200.80 = 555.55 : x
  2. Step 2: Convert to fraction form
    869.86/1,200.80 = 555.55/x
  3. Step 3: Cross multiply
    869.86x = 1,200.80 × 555.55
  4. Step 4: Simplify right side
    869.86x = 667,104.44
  5. Step 5: Solve for x
    x = 667,104.44/869.86
  6. Step 6: Final answer
    x = 766.91

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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.