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Finding the Fourth Proportional to 328.10, 491.34 and 278.78

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Solution

The fourth proportional to 328.10, 491.34 and 278.78 is: 417.48

Step by Step Solution

  1. Step 1: Write the proportion equation
    328.10 : 491.34 = 278.78 : x
  2. Step 2: Convert to fraction form
    328.10/491.34 = 278.78/x
  3. Step 3: Cross multiply
    328.10x = 491.34 × 278.78
  4. Step 4: Simplify right side
    328.10x = 136,975.77
  5. Step 5: Solve for x
    x = 136,975.77/328.10
  6. Step 6: Final answer
    x = 417.48

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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.