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Finding the Fourth Proportional to 859.03, 1,288.35 and 420.28

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Solution

The fourth proportional to 859.03, 1,288.35 and 420.28 is: 630.32

Step by Step Solution

  1. Step 1: Write the proportion equation
    859.03 : 1,288.35 = 420.28 : x
  2. Step 2: Convert to fraction form
    859.03/1,288.35 = 420.28/x
  3. Step 3: Cross multiply
    859.03x = 1,288.35 × 420.28
  4. Step 4: Simplify right side
    859.03x = 541,467.74
  5. Step 5: Solve for x
    x = 541,467.74/859.03
  6. Step 6: Final answer
    x = 630.32

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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.