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Finding the Fourth Proportional to 689.45, 1,034.35 and 278.49

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Solution

The fourth proportional to 689.45, 1,034.35 and 278.49 is: 417.81

Step by Step Solution

  1. Step 1: Write the proportion equation
    689.45 : 1,034.35 = 278.49 : x
  2. Step 2: Convert to fraction form
    689.45/1,034.35 = 278.49/x
  3. Step 3: Cross multiply
    689.45x = 1,034.35 × 278.49
  4. Step 4: Simplify right side
    689.45x = 288,055.06
  5. Step 5: Solve for x
    x = 288,055.06/689.45
  6. Step 6: Final answer
    x = 417.81

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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.