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Finding the Fourth Proportional to 899.49, 1,349.45 and 640

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Solution

The fourth proportional to 899.49, 1,349.45 and 640 is: 960.15

Step by Step Solution

  1. Step 1: Write the proportion equation
    899.49 : 1,349.45 = 640 : x
  2. Step 2: Convert to fraction form
    899.49/1,349.45 = 640/x
  3. Step 3: Cross multiply
    899.49x = 1,349.45 × 640
  4. Step 4: Simplify right side
    899.49x = 863,648
  5. Step 5: Solve for x
    x = 863,648/899.49
  6. Step 6: Final answer
    x = 960.15

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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.