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Finding the Fourth Proportional to 815.69, 1,222.31 and 328.47

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Solution

The fourth proportional to 815.69, 1,222.31 and 328.47 is: 492.21

Step by Step Solution

  1. Step 1: Write the proportion equation
    815.69 : 1,222.31 = 328.47 : x
  2. Step 2: Convert to fraction form
    815.69/1,222.31 = 328.47/x
  3. Step 3: Cross multiply
    815.69x = 1,222.31 × 328.47
  4. Step 4: Simplify right side
    815.69x = 401,492.17
  5. Step 5: Solve for x
    x = 401,492.17/815.69
  6. Step 6: Final answer
    x = 492.21

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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.