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Finding the Fourth Proportional to 719.88, 1,080 and 287.16

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Solution

The fourth proportional to 719.88, 1,080 and 287.16 is: 430.81

Step by Step Solution

  1. Step 1: Write the proportion equation
    719.88 : 1,080 = 287.16 : x
  2. Step 2: Convert to fraction form
    719.88/1,080 = 287.16/x
  3. Step 3: Cross multiply
    719.88x = 1,080 × 287.16
  4. Step 4: Simplify right side
    719.88x = 310,132.80
  5. Step 5: Solve for x
    x = 310,132.80/719.88
  6. Step 6: Final answer
    x = 430.81

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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.