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Finding the Fourth Proportional to 661.77, 988.00 and 639.09

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Solution

The fourth proportional to 661.77, 988.00 and 639.09 is: 954.14

Step by Step Solution

  1. Step 1: Write the proportion equation
    661.77 : 988.00 = 639.09 : x
  2. Step 2: Convert to fraction form
    661.77/988.00 = 639.09/x
  3. Step 3: Cross multiply
    661.77x = 988.00 × 639.09
  4. Step 4: Simplify right side
    661.77x = 631,419.32
  5. Step 5: Solve for x
    x = 631,419.32/661.77
  6. Step 6: Final answer
    x = 954.14

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.