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Finding the Fourth Proportional to 649.76, 974.78 and 420.26

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Solution

The fourth proportional to 649.76, 974.78 and 420.26 is: 630.48

Step by Step Solution

  1. Step 1: Write the proportion equation
    649.76 : 974.78 = 420.26 : x
  2. Step 2: Convert to fraction form
    649.76/974.78 = 420.26/x
  3. Step 3: Cross multiply
    649.76x = 974.78 × 420.26
  4. Step 4: Simplify right side
    649.76x = 409,661.04
  5. Step 5: Solve for x
    x = 409,661.04/649.76
  6. Step 6: Final answer
    x = 630.48

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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.