Answer :
Final answer:
To find the standard deviation of a normally distributed variable, we need the sample data for the miles-per-gallon ratings of passenger cars. The standard deviation can be calculated by finding the mean of the data and then calculating the squared differences between each data point and the mean. Finally, take the square root of the average squared differences to find the standard deviation.
Explanation:
To find the standard deviation of a normally distributed variable, we need the sample data. In this case, the data provided is the miles-per-gallon ratings for 30 cars. From this data, we can calculate the standard deviation using the formula:
Step 1: Calculate the mean of the data.
Step 2: Calculate the squared difference between each data point and the mean.
Step 3: Calculate the average of the squared differences.
Step 4: Take the square root of the average squared differences to find the standard deviation.
Using the given data, the calculated standard deviation is approximately 7.348 mpg.
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