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Finding the Fourth Proportional to 328.23, 489.94 and 285.21

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Solution

The fourth proportional to 328.23, 489.94 and 285.21 is: 425.72

Step by Step Solution

  1. Step 1: Write the proportion equation
    328.23 : 489.94 = 285.21 : x
  2. Step 2: Convert to fraction form
    328.23/489.94 = 285.21/x
  3. Step 3: Cross multiply
    328.23x = 489.94 × 285.21
  4. Step 4: Simplify right side
    328.23x = 139,735.07
  5. Step 5: Solve for x
    x = 139,735.07/328.23
  6. Step 6: Final answer
    x = 425.72

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.