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Finding the Fourth Proportional to 852.64, 1,278.86 and 407.80

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Solution

The fourth proportional to 852.64, 1,278.86 and 407.80 is: 611.65

Step by Step Solution

  1. Step 1: Write the proportion equation
    852.64 : 1,278.86 = 407.80 : x
  2. Step 2: Convert to fraction form
    852.64/1,278.86 = 407.80/x
  3. Step 3: Cross multiply
    852.64x = 1,278.86 × 407.80
  4. Step 4: Simplify right side
    852.64x = 521,519.11
  5. Step 5: Solve for x
    x = 521,519.11/852.64
  6. Step 6: Final answer
    x = 611.65

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.