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Finding the Fourth Proportional to 719.93, 1,080.42 and 287.21

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Solution

The fourth proportional to 719.93, 1,080.42 and 287.21 is: 431.02

Step by Step Solution

  1. Step 1: Write the proportion equation
    719.93 : 1,080.42 = 287.21 : x
  2. Step 2: Convert to fraction form
    719.93/1,080.42 = 287.21/x
  3. Step 3: Cross multiply
    719.93x = 1,080.42 × 287.21
  4. Step 4: Simplify right side
    719.93x = 310,307.43
  5. Step 5: Solve for x
    x = 310,307.43/719.93
  6. Step 6: Final answer
    x = 431.02

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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.