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Finding the Fourth Proportional to 426.51, 640.28 and 287.80

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Solution

The fourth proportional to 426.51, 640.28 and 287.80 is: 432.05

Step by Step Solution

  1. Step 1: Write the proportion equation
    426.51 : 640.28 = 287.80 : x
  2. Step 2: Convert to fraction form
    426.51/640.28 = 287.80/x
  3. Step 3: Cross multiply
    426.51x = 640.28 × 287.80
  4. Step 4: Simplify right side
    426.51x = 184,271.70
  5. Step 5: Solve for x
    x = 184,271.70/426.51
  6. Step 6: Final answer
    x = 432.05

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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.