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Finding the Fourth Proportional to 328.24, 491.28 and 287.20

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Solution

The fourth proportional to 328.24, 491.28 and 287.20 is: 429.86

Step by Step Solution

  1. Step 1: Write the proportion equation
    328.24 : 491.28 = 287.20 : x
  2. Step 2: Convert to fraction form
    328.24/491.28 = 287.20/x
  3. Step 3: Cross multiply
    328.24x = 491.28 × 287.20
  4. Step 4: Simplify right side
    328.24x = 141,095.62
  5. Step 5: Solve for x
    x = 141,095.62/328.24
  6. Step 6: Final answer
    x = 429.86

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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.