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Finding the Fourth Proportional to 849.88, 1,171.38 and 640

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Solution

The fourth proportional to 849.88, 1,171.38 and 640 is: 882.10

Step by Step Solution

  1. Step 1: Write the proportion equation
    849.88 : 1,171.38 = 640 : x
  2. Step 2: Convert to fraction form
    849.88/1,171.38 = 640/x
  3. Step 3: Cross multiply
    849.88x = 1,171.38 × 640
  4. Step 4: Simplify right side
    849.88x = 749,683.20
  5. Step 5: Solve for x
    x = 749,683.20/849.88
  6. Step 6: Final answer
    x = 882.10

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.