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Finding the Fourth Proportional to 815.04, 1,221.80 and 328.42

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Solution

The fourth proportional to 815.04, 1,221.80 and 328.42 is: 492.32

Step by Step Solution

  1. Step 1: Write the proportion equation
    815.04 : 1,221.80 = 328.42 : x
  2. Step 2: Convert to fraction form
    815.04/1,221.80 = 328.42/x
  3. Step 3: Cross multiply
    815.04x = 1,221.80 × 328.42
  4. Step 4: Simplify right side
    815.04x = 401,263.56
  5. Step 5: Solve for x
    x = 401,263.56/815.04
  6. Step 6: Final answer
    x = 492.32

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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.