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Finding the Fourth Proportional to 649.28, 890.86 and 643.16

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Solution

The fourth proportional to 649.28, 890.86 and 643.16 is: 882.46

Step by Step Solution

  1. Step 1: Write the proportion equation
    649.28 : 890.86 = 643.16 : x
  2. Step 2: Convert to fraction form
    649.28/890.86 = 643.16/x
  3. Step 3: Cross multiply
    649.28x = 890.86 × 643.16
  4. Step 4: Simplify right side
    649.28x = 572,965.52
  5. Step 5: Solve for x
    x = 572,965.52/649.28
  6. Step 6: Final answer
    x = 882.46

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Why These Related Problems?

These problems maintain the same ratio (1.37) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.