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Finding the Fourth Proportional to 328.36, 491.78 and 258.38

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Solution

The fourth proportional to 328.36, 491.78 and 258.38 is: 386.97

Step by Step Solution

  1. Step 1: Write the proportion equation
    328.36 : 491.78 = 258.38 : x
  2. Step 2: Convert to fraction form
    328.36/491.78 = 258.38/x
  3. Step 3: Cross multiply
    328.36x = 491.78 × 258.38
  4. Step 4: Simplify right side
    328.36x = 127,066.12
  5. Step 5: Solve for x
    x = 127,066.12/328.36
  6. Step 6: Final answer
    x = 386.97

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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.