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Finding the Fourth Proportional to 689.42, 1,034.45 and 278.55

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Solution

The fourth proportional to 689.42, 1,034.45 and 278.55 is: 417.95

Step by Step Solution

  1. Step 1: Write the proportion equation
    689.42 : 1,034.45 = 278.55 : x
  2. Step 2: Convert to fraction form
    689.42/1,034.45 = 278.55/x
  3. Step 3: Cross multiply
    689.42x = 1,034.45 × 278.55
  4. Step 4: Simplify right side
    689.42x = 288,146.05
  5. Step 5: Solve for x
    x = 288,146.05/689.42
  6. Step 6: Final answer
    x = 417.95

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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.