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Finding the Fourth Proportional to 855.90, 1,283.69 and 278.64

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Solution

The fourth proportional to 855.90, 1,283.69 and 278.64 is: 417.91

Step by Step Solution

  1. Step 1: Write the proportion equation
    855.90 : 1,283.69 = 278.64 : x
  2. Step 2: Convert to fraction form
    855.90/1,283.69 = 278.64/x
  3. Step 3: Cross multiply
    855.90x = 1,283.69 × 278.64
  4. Step 4: Simplify right side
    855.90x = 357,685.99
  5. Step 5: Solve for x
    x = 357,685.99/855.90
  6. Step 6: Final answer
    x = 417.91

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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.