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Finding the Fourth Proportional to 690.12, 1,034.40 and 279

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Solution

The fourth proportional to 690.12, 1,034.40 and 279 is: 418.18

Step by Step Solution

  1. Step 1: Write the proportion equation
    690.12 : 1,034.40 = 279 : x
  2. Step 2: Convert to fraction form
    690.12/1,034.40 = 279/x
  3. Step 3: Cross multiply
    690.12x = 1,034.40 × 279
  4. Step 4: Simplify right side
    690.12x = 288,597.60
  5. Step 5: Solve for x
    x = 288,597.60/690.12
  6. Step 6: Final answer
    x = 418.18

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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.