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Finding the Fourth Proportional to 815.69, 1,223.69 and 328.74

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Solution

The fourth proportional to 815.69, 1,223.69 and 328.74 is: 493.17

Step by Step Solution

  1. Step 1: Write the proportion equation
    815.69 : 1,223.69 = 328.74 : x
  2. Step 2: Convert to fraction form
    815.69/1,223.69 = 328.74/x
  3. Step 3: Cross multiply
    815.69x = 1,223.69 × 328.74
  4. Step 4: Simplify right side
    815.69x = 402,274.21
  5. Step 5: Solve for x
    x = 402,274.21/815.69
  6. Step 6: Final answer
    x = 493.17

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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.