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Finding the Fourth Proportional to 853.05, 1,278.36 and 420.51

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Solution

The fourth proportional to 853.05, 1,278.36 and 420.51 is: 630.17

Step by Step Solution

  1. Step 1: Write the proportion equation
    853.05 : 1,278.36 = 420.51 : x
  2. Step 2: Convert to fraction form
    853.05/1,278.36 = 420.51/x
  3. Step 3: Cross multiply
    853.05x = 1,278.36 × 420.51
  4. Step 4: Simplify right side
    853.05x = 537,563.16
  5. Step 5: Solve for x
    x = 537,563.16/853.05
  6. Step 6: Final answer
    x = 630.17

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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.