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Finding the Fourth Proportional to 853.19, 1,279.78 and 305.39

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Solution

The fourth proportional to 853.19, 1,279.78 and 305.39 is: 458.08

Step by Step Solution

  1. Step 1: Write the proportion equation
    853.19 : 1,279.78 = 305.39 : x
  2. Step 2: Convert to fraction form
    853.19/1,279.78 = 305.39/x
  3. Step 3: Cross multiply
    853.19x = 1,279.78 × 305.39
  4. Step 4: Simplify right side
    853.19x = 390,832.01
  5. Step 5: Solve for x
    x = 390,832.01/853.19
  6. Step 6: Final answer
    x = 458.08

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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.