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Finding the Fourth Proportional to 716.28, 988.38 and 421.64

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Solution

The fourth proportional to 716.28, 988.38 and 421.64 is: 581.81

Step by Step Solution

  1. Step 1: Write the proportion equation
    716.28 : 988.38 = 421.64 : x
  2. Step 2: Convert to fraction form
    716.28/988.38 = 421.64/x
  3. Step 3: Cross multiply
    716.28x = 988.38 × 421.64
  4. Step 4: Simplify right side
    716.28x = 416,740.54
  5. Step 5: Solve for x
    x = 416,740.54/716.28
  6. Step 6: Final answer
    x = 581.81

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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.