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Finding the Fourth Proportional to 688.80, 1,033.70 and 278.05

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Solution

The fourth proportional to 688.80, 1,033.70 and 278.05 is: 417.27

Step by Step Solution

  1. Step 1: Write the proportion equation
    688.80 : 1,033.70 = 278.05 : x
  2. Step 2: Convert to fraction form
    688.80/1,033.70 = 278.05/x
  3. Step 3: Cross multiply
    688.80x = 1,033.70 × 278.05
  4. Step 4: Simplify right side
    688.80x = 287,416.31
  5. Step 5: Solve for x
    x = 287,416.31/688.80
  6. Step 6: Final answer
    x = 417.27

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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.