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Finding the Fourth Proportional to 708.44, 977.80 and 639.20

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Solution

The fourth proportional to 708.44, 977.80 and 639.20 is: 882.23

Step by Step Solution

  1. Step 1: Write the proportion equation
    708.44 : 977.80 = 639.20 : x
  2. Step 2: Convert to fraction form
    708.44/977.80 = 639.20/x
  3. Step 3: Cross multiply
    708.44x = 977.80 × 639.20
  4. Step 4: Simplify right side
    708.44x = 625,009.76
  5. Step 5: Solve for x
    x = 625,009.76/708.44
  6. Step 6: Final answer
    x = 882.23

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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.