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Finding the Fourth Proportional to 764.05, 1,145.79 and 398.80

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Solution

The fourth proportional to 764.05, 1,145.79 and 398.80 is: 598.05

Step by Step Solution

  1. Step 1: Write the proportion equation
    764.05 : 1,145.79 = 398.80 : x
  2. Step 2: Convert to fraction form
    764.05/1,145.79 = 398.80/x
  3. Step 3: Cross multiply
    764.05x = 1,145.79 × 398.80
  4. Step 4: Simplify right side
    764.05x = 456,941.05
  5. Step 5: Solve for x
    x = 456,941.05/764.05
  6. Step 6: Final answer
    x = 598.05

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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.