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Finding the Fourth Proportional to 849.80, 1,274.70 and 720.20

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Solution

The fourth proportional to 849.80, 1,274.70 and 720.20 is: 1,080.30

Step by Step Solution

  1. Step 1: Write the proportion equation
    849.80 : 1,274.70 = 720.20 : x
  2. Step 2: Convert to fraction form
    849.80/1,274.70 = 720.20/x
  3. Step 3: Cross multiply
    849.80x = 1,274.70 × 720.20
  4. Step 4: Simplify right side
    849.80x = 918,038.94
  5. Step 5: Solve for x
    x = 918,038.94/849.80
  6. Step 6: Final answer
    x = 1,080.30

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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.