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Finding the Fourth Proportional to 720.27, 1,075.84 and 639.63

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Solution

The fourth proportional to 720.27, 1,075.84 and 639.63 is: 955.39

Step by Step Solution

  1. Step 1: Write the proportion equation
    720.27 : 1,075.84 = 639.63 : x
  2. Step 2: Convert to fraction form
    720.27/1,075.84 = 639.63/x
  3. Step 3: Cross multiply
    720.27x = 1,075.84 × 639.63
  4. Step 4: Simplify right side
    720.27x = 688,137.94
  5. Step 5: Solve for x
    x = 688,137.94/720.27
  6. Step 6: Final answer
    x = 955.39

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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.